Tools
All Free Tools
680 free tools · No signup, no limits, no cost.
Compare your current mortgage to a refinance offer — break-even months, monthly savings, lifetime interest cut.
Compare up to three loan offers side-by-side — true cost, effective APR, total interest.
What if my rate rises? Stress-test your mortgage at +1pp / +2pp / +3pp and find your break-point.
Full amortisation schedule with extra-payment accelerator — see months saved and interest cut.
Compare snowball vs avalanche on your real debt portfolio — months saved, interest cost, payoff order.
The canonical SaaS scoreboard — MRR, ARR, NRR, GRR, and growth rate from your four monthly movements.
Customer LTV the SaaS-canonical way — simple formula plus cohort-weighted DCF for investor-grade math.
CAC, payback months, and LTV:CAC ratio — the three numbers every SaaS investor asks for.
Net burn, runway months, cash-out date, plus cost-cut scenario — Default Alive vs Dead in one tile.
Every ad-platform performance metric from four inputs — for Google, Meta, LinkedIn, TikTok.
How much the minimum-payment trap costs you — and what 2× / 3× payments save.
Convert APR ↔ APY for any compounding frequency. The math savings accounts and lenders use.
True cost of borrowing with compounding. The loan-side companion to APR/APY.
The 500-year-old mental math shortcut every investor uses. How long does money take to double?
Pure-math salary ↔ hourly converter with work-hour and vacation toggles.
Project portfolio value from monthly contributions. The boring strategy that wins most years.
DRIP vs cash dividends side-by-side. The highest-leverage dividend habit.
Risk-per-trade math the single most important skill in active trading.
Pip value + risk-based lot size for every major forex pair.
YTM, YTC, current yield, and modified duration for any fixed-income bond.
Personal balance sheet — assets minus liabilities. Runs entirely in your browser.
How long until you can buy. FHA / Conventional / 20% scenarios computed.
After-tax value of US equity grants with ISO / NSO / RSU + AMT modelling.
Founder ownership through seed, A, B, C — dilution math the venture canon uses.
Multi-founder + multi-SAFE + priced round. The YC standard cap-table math.
Even split + US tip presets. The fastest way to settle group dinner.
Per-item split with proportional tax + tip. The "I only had a salad" calculator.
Trip fuel cost in MPG or L/100km, plus gas vs EV side-by-side.
Full road-trip budget: fuel + lodging + food + tolls. Per-traveller share included.
Target hourly rate with SE tax, benefits gap, and real billable hours baked in.
Daily clock-in/out → weekly hours + FLSA-style overtime split.
Three-point estimation with 68/95/99% confidence intervals.
Velocity-based release forecast with best/likely/worst ranges.
Markup ↔ Margin conversion + cost-plus / margin-target pricing math.
Fixed costs ÷ contribution margin — and margin-of-safety risk frame.
%Promoters − %Detractors. Plus industry benchmarks + 95% CI.
Multi-step funnel with worst-step flagged — CRO leverage finder.
Two-proportion z-test sample size with days-to-run estimate.
p-value + 95% CI + ship/no-ship verdict for finished A/B tests.
Channel ROAS + blended MER + break-even ROAS + POAS in one view.
Employer-match optimizer + IRS-limit-aware 401(k) growth projection.
Traditional vs Roth side-by-side — with side-savings credit most calculators miss.
62 vs 67 vs 70 — cumulative lifetime benefit + pairwise break-even ages.
IRS Uniform Lifetime Table + SECURE 2.0 ages — current-year + 10-year projection.
The 4% rule, refined. Plus the FIRE-number side-bar most beginners want.
DIME + 10× Income + Human Life Value — median verdict beats any single rule of thumb.
Identifies the tax-treatment gap most LTD calculators miss.
Self-fund vs traditional vs hybrid LTC — Genworth cost survey baked in.
HSA triple-tax-advantage vs FSA use-it-or-lose-it — with the receipt-strategy unlock.
Part B + IRMAA + Part D + Medigap — the full Medicare cost stack with surprise-tax surfacing.
Full BiggerPockets-style analyzer — NOI, cap rate, CoC, with 1%-rule + 50%-rule checks.
NYT-style total cost comparison with opportunity-cost-of-down-payment built in.
David Greene's capital-recycling strategy — tests whether your deal is truly "infinite return".
STR cash flow vs LTR side-by-side — with STR-specific operating cost reality.
Defer-or-pay analysis with full boot-exposure surfacing and step-up-at-death framing.
US crypto cap gains with NIIT + state tax stacking. ST vs LT bracket math.
APR→APY at any compounding frequency + gas-cost impact on net yield.
Coin growth + USD value scenarios + validator fee + US tax on rewards.
Gwei × ETH price → USD per common tx type, with L1 vs L2 split.
DCA vs lump-sum side-by-side, with crypto-specific volatility assumptions.
Amortization + DSCR check — the math lenders use on every business loan application.
8-test SBA pre-qualification screen for 7(a), 504, Express.
SDE × industry multiple with qualitative adjustments. Low / mid / high range.
The 1.25-1.45× multiplier most hiring managers underestimate.
Sole Prop vs LLC vs S-Corp vs C-Corp side-by-side with QBI + SE tax math.
2026 brackets with bracket-by-bracket breakdown + marginal vs effective rate.
ST vs LT cap gains + NIIT + state tax stacking.
529 vs taxable + state deduction + projected college cost coverage %.
CTC + ACTC + ODC with income phase-out math.
The young-professional dilemma: pay it down or invest it.
Net Present Value + decision verdict
IRR + MIRR via Newton-Raphson
Financial independence target + timeline
One-and-done FIRE milestone
Income vs expenses + years to FIRE
Purchasing power across years
Fisher equation real return
Income allocation framework
Risk-adjusted return
Pay off your mortgage faster
The 26-payment payoff hack
Home equity line of credit math
Capture every dollar of free money
The tax-arbitrage decision
The canonical SaaS health metric
Growth + margin ≥ 40 = healthy
SaaS growth efficiency multiplier
Sales efficiency for SaaS
This should have been an email
Retention matrix + heatmap
Buy/sell per asset to restore targets
Age + risk → recommended split
Max drawdown + recovery chart
Entry/stop/target → R:R + position size
Forward + reverse split impact
Renovation cost vs resale uplift
NOI / Value, commercial fundamental
Leveraged rental yield
Quick rental screening metric
Rent vs buy decision framework
Vacant units ÷ total + lost income
DIO + DSO − DPO; days cash tied up
CA − CL + current + quick ratios
Days customers take to pay
Anchor → Good/Better/Best ladder + ARR
DIME + income multiplier methods
30-year cost + BTID math
Income gap analysis
BS-Merton 1973 — call + put pricer
Δ Γ Θ ν ρ — risk-management sensitivities
Reverse BS — solve σ from market price
DCF — discount FCF at WACC + Gordon TV
WACC — blended hurdle rate for DCF
CAPM — cost of equity from β
How much house can I afford? (28/36 rule)
Year-by-year P&I schedule
PMI cost + HOPA auto-cancel timing
Gordon + 2-stage DDM — intrinsic value
Trailing + forward P/E + Fed Model
Peter Lynch's growth-adjusted P/E
FCFF + FCFE — DCF inputs
3F + 5F ROE decomposition
Book + market D/E + leverage chips
1968 bankruptcy prediction
Income options strategy
4-leg defined-risk theta strategy
Reg T + maintenance + margin call
Discount points breakeven
ARM vs fixed-rate breakeven
Itemized closing estimate
CoC + cap rate + total ROI
Buy-Rehab-Rent-Refi-Repeat strategy
70% rule + flip P&L
Month-by-month payment + interest breakdown
Compare cashback, points & miles across cards
Solve for PV, FV, PMT, N, or rate
Macaulay & modified duration
Second-order rate sensitivity
Muni vs taxable bond yield
15% discount + lookback gain
RSU / option vesting tracker
Supplemental withholding + sell-to-cover
Deduct + grow + withdraw, all tax-free
Historical success rate by rate + allocation
Overall + per-card ratio vs the 30% line
Time + interest saved from extra payments
Net housing cost + cash-on-cash return
Lower payment after a lump sum — no refinance
Rent credits, net price + the premium you pay
Points + interest carry + flip profit
Equity by year from paydown + appreciation
Rough injury-claim ranges — not legal advice
Convert between 170+ currencies with live exchange rates — SGD, MYR, IDR, THB and more.
Calculate your mortgage repayments for HDB, BTO and private property — SGD, MYR and more.
Calculate loan EMI and total interest
See how your money grows over time — with compound interest, CPF, and investment planning.
Calculate GST/VAT for SG, MY, ID, TH
Calculate if you are on track for retirement — with CPF projections and ASEAN retirement planning.
Convert salary between hourly, daily, monthly and annual — with Singapore CPF and income tax estimates.
Plan monthly income and expenses
Find your break-even point in units and revenue — essential for pricing, planning and startup financial decisions.
Calculate sale prices, savings and discount percentages instantly — with GST-inclusive options for Singapore.
Calculate gross profit, net profit and markup percentage — essential for pricing and business decisions.
Generate simple invoices as PDF
Calculate monthly repayments for any loan — home, car, personal or business.
Calculate Singapore (YA 2026) and Malaysia (YA 2025) personal income tax with CPF/EPF — side-by-side, with all current brackets and reliefs.
Calculate tips and split bills instantly — for restaurants, delivery and group dining.
Add or remove GST and sales tax instantly — Singapore 9%, Malaysia 8%, Thailand 7% and more.
Calculate investment returns, ROI and annualised growth rate — for stocks, ETFs and savings.
Validate IBANs with mod-97 checksum, format-as-you-type, and country breakdown.
Aerobic capacity benchmark
Riegel formula across distances
Target time → pace + splits
L/hr sweat + hydration plan
FTP + W/kg + Coggan zones
5-formula 1RM average + % table
WHtR — better than BMI
Boer + Hume + James formulas
Decay tracker + sleep cutoff
Widmark formula (educational only)
Tanaka/Fox/Gulati/Nes equations
Mifflin-St Jeor + TDEE multipliers
Karvonen HRR 5-zone method
MET-based, 35+ activities
Protein/carb/fat from goal
Predict a child's adult height from the parents
Likely conception date, fertile window + due date
Calculate your BMI instantly using ASEAN health thresholds — metric and imperial.
Calculate your daily calorie needs in seconds — enter your details and get your maintenance calories instantly.
Calculate your ideal daily water intake based on weight, activity and climate — with ASEAN tropical heat adjustment.
Estimate your body fat percentage using the Navy method — with ASEAN-specific health ranges.
Find your ideal weight range using 5 medical formulas — with ASEAN-adjusted healthy ranges.
Calculate your pregnancy due date and current week — enter your last period or conception date.
Find the best times to wake up or go to sleep based on 90-minute sleep cycles — wake up refreshed, not groggy.
Calculate target heart rate zones
Calculate your daily protein, carbs and fat targets — based on your body, goals and activity level.
Calculate your daily calorie needs based on age, weight, height and activity level.
Calculate Unix file permissions instantly — switch between octal (755), symbolic (-rwxr-xr-x) and a visual checkbox grid. Includes special bits (setuid, setgid, sticky).
WCAG 2.1 AA/AAA accessibility
Modular typography scale
px ↔ rem ↔ em ↔ pt
Epoch ↔ ISO 8601 ↔ local time
8 CVD types — colors + images
Multi-layer shadow stacks
Draggable easing curve editor
Polygon vertex editor
View, sort, and convert CSV to JSON, SQL, XML, or Markdown
Build, describe, and test crontab schedules
Convert Markdown to a clean PDF, with LaTeX math
Encode text to HTML entities, or decode them back
Convert names between camelCase, snake_case, kebab-case & more
Build a .gitignore from your stack, OS and editor
Turn CSV or pasted data into a clean Markdown table
Generate QR codes for URLs, text, Wi-Fi, vCard, and more
Format, validate and minify JSON instantly — with clear error messages and line numbers.
Convert between binary, octal, decimal and hexadecimal — instantly.
Generate strong, random passwords with custom length and character rules.
Generate favicons in all sizes from any image or text — download ready-to-use ICO, PNG and SVG files.
Generate UUIDs v1/v4 and ULIDs instantly — bulk generation, multiple formats.
Generate MD5, SHA-1, SHA-256 and SHA-512 hashes instantly — for passwords, files and data integrity.
Test and debug regular expressions in real time — with match highlighting, groups and a built-in reference.
Pick colours and convert between HEX, RGB, HSL and CMYK — with CSS snippets ready to copy.
Generate CSS gradient code visually
Build and validate cron expressions
Decode and inspect any JWT token instantly — header, payload, expiry and signature details, all in your browser.
Find your public IP address and look up any IP's location, ISP and organisation instantly.
Look up every HTTP status code instantly — with plain-English descriptions, use cases and fix tips.
Encode text or files to Base64 and decode Base64 strings — instantly, in your browser.
Convert colours between HEX, RGB, HSL and CMYK — with live preview.
Encode and decode URLs and query strings instantly — with full RFC 3986 component support.
Build structured AI prompts using CRAFT, RTF, RACE, CO-STAR, RISEN, APE — 6 industry frameworks + 30 templates + ChatGPT/Claude/Gemini-tuned output.
Type Markdown on the left, see HTML preview on the right. GitHub-flavored: headings, lists, tables, code blocks, task lists. In-browser, no signup.
Search, copy, and test regular expressions instantly.
Strip dot tricks, plus-aliases, and capitalisation to find the underlying email.
Calculate network, broadcast, host range, and subnets from CIDR or netmask.
Build and validate cron expressions with a visual editor and next-5-runs preview.
Decode browser, OS, device type, and bot signals from any User-Agent string.
Generate random MACs and look up vendor (OUI) for any MAC address.
Build the WiFi-connect string (SSID + password + security) for QR sharing.
Parse and format international phone numbers with libphonenumber. Country dropdown defaults to ASEAN.
Convert a docker run command to docker-compose.yml — handles ports, volumes, env, restart, networks.
Convert between JSON, YAML, XML, and CSV. Auto-detect input format, side-by-side editors, all client-side.
Char + pixel width vs SERP cutoff
SERP snippet length validator
Words → minutes @ 238 wpm
Score headlines 0-100
JSON-LD FAQPage for rich snippets
Generate complete meta tags for SEO, Open Graph and Twitter Cards — copy ready.
Analyse keyword density in any text — find over-optimised and under-used terms before publishing.
Convert any title or phrase into a clean URL slug — for SEO, CMS and development.
Preview Open Graph social media cards
Generate robots.txt for your website
Build an XML sitemap manually — add your URLs, set priority and change frequency, download ready for Google.
Build UTM tracking URLs for campaigns
nPr, nCr, factorial (BigInt)
Mean, SD, variance, quartiles
Standard score + percentile + p-value
CI for mean + proportion
Slope + intercept + r + R² + scatter
Days/months/years between dates
Business days with ASEAN holidays
Date arithmetic + day of week
ISO 8601 + US week numbering
HH:MM:SS arithmetic + decimal
One-sample / Welch / paired
Goodness-of-fit + independence
F-test + eta-squared
Cochran + A/B test power
ax^2+bx+c=0 real + complex
SSS/SAS/ASA/AAS/SSA
HKD → Traditional Chinese cheque format
RMB → Simplified Chinese invoice format
Bidirectional Gregorian ↔ Chinese lunar
虚岁 / 实岁 dual age
八宅命卦 + 8 directions
4-pillar birth chart + 五行 + 十神
Two birth years → 六合/三合/相冲
8 chars → 五行 distribution + 补救
Two charts → 3-axis compat
General 黄道吉日 picker
宜嫁娶 + bride/groom zodiac
宜入宅/移徙 + owner zodiac
宜开市/开张 + owner zodiac
Any date → 60甲子 stem-branch
Year → 生肖 + 干支 + 纳音
Year → 24 节气 exact dates + times
4 formats: standard / written / lunar / 干支
NTD → Traditional capital cheque format
3 formats: 一二三 / 壹贰叁 / 壹貳叁
Budget + occasion → 12 lucky amounts
Number → per-digit lucky/avoid + score
Hanzi → 5 pinyin formats + polyphone
Hanzi → ㄅㄆㄇㄈ Taiwan standard
ni3 hao3 ↔ ㄋㄧˇ ㄏㄠˇ
Per-character stroke count + stroke-order SVG
214 Kangxi radicals grouped by stroke count
天格・人格・地格・外格・总格 numerology
Curated character pool by element + stroke
1-81 数理吉凶 auspice analysis
Top 50 surnames · clan history · diaspora romanisations
80 curated 4-character idioms · pinyin · classical origin · modern usage
HSK 1-6 vocab · 25 representative words per level
Top 200 high-frequency chars · Jun Da corpus · cumulative coverage %
Hanzi → Jyutping · LSHK 1993 standard · 6 tones + IPA
Hanzi → Yale · 1970s US standard · numeric + diacritic
4 tones + neutral quiz · build tone-recognition reflexes
cn ↔ tw ↔ hk · OpenCC-powered · word-level conversion
Full-width ↔ half-width punctuation + ASCII
Top-to-bottom, right-to-left classical layout + print
8 toggleable rules · OCR/clipboard cleanup · privacy-safe
hanzi-writer-powered SVG · 9000+ chars · ARPHIC data
80 curated classical particles + function words
64 hexagrams · line patterns · trigrams · coin-cast simulation
六大茶类 · gongfu method · live countdown + audio beep
11 major festivals · Gregorian dates · traditions
Hong Kong fan scoring · base × 2^min(fan, cap) · HK/SG/MY
Full 9×10 board · 32 pieces · click-to-move · auto-notation (Chinese + WXF)
50 classic HK dim sum · Jyutping · category · price tier
10 traditional knot patterns · cultural meanings · difficulty
24 traditional colors · hex codes · cultural meanings
40+ classic 春联 by 7 themes · vertical 上下联 + 横披 · print PDF
18 numbers · homophones · luck ratings · cultural usage
18 auspicious symbols · meanings · classical origins
Digital luopan compass · 24 mountains + 8 trigrams · phone magnetometer
8-Mansion feng shui · life trigram + 8-zone home map · door direction
Bazi vs annual Tai Sui · zodiac & 5-element interaction
4-pillar 十神 breakdown · 5-category distribution · interpretation
10-year 大运 cycles · GanZhi · Ten God · 5-element
用神 (useful god) · colors + directions + industries
5 Grids · 3 Talents · 81 numerology · overall score
3-way zodiac · recommended baby zodiac years
Daily/weekly/monthly · 4 domains · lucky color/direction/number
5 regions × 3 tiers · bride price + dowry + banquet
Score & rank candidate numbers · 168/888 vs 444/514
Person-house compatibility · sunlight · 6 layout taboos
Verifies the S/T/F/G/M check-letter algorithm · browser-only
12-digit format + birth date + state code · browser-only
SG / MY / HK / TW / CN / PH / ID / TH / VN · format check
1-2 letter + 6 digit + check character · Mod 11 algorithm
1 letter + 9 digits · region + gender + checksum
18-digit ISO 7064 MOD 11-2 · region + birth + gender
6-digit postcode → District (D01-D28) + Planning Area + Region
5-digit postcode → state + postal zone (Pos Malaysia)
33 provincial-level divisions · GB/T 2260 standard
HK Island 4 + Kowloon 5 + New Territories 9 · with codes
6 special municipalities + 3 cities + 13 counties · with ID letter
Drag-and-drop tree · auto relationship labels · SVG / PNG export
6 dialects · 拼音 / 粤拼 / 闽南罗马字 / 客拼 · up to 4 generations
30 major surnames' 字辈/字派 · root-tracing + naming
yyds / 666 / 内卷 / 躺平 · 50+ terms · 2000s-2020s
70+ nouns → 量词 · 一本书 / 一只猫 / 一双鞋
GB/T 15834-2011 · auto-detect + auto-fix · ASCII → 全角
60 chengyu · pinyin + literal + English equivalent (画蛇添足 = gild the lily)
平水韵 24 + 中华新韵 14 · 古典 + 现代诗词押韵
40 首精选 · 李白 杜甫 王维 白居易 · 拼音 + 英文背景
横排 → 竖排 · 右起 / 左起 · 标点旋转 90° 可选
30 组 · 形近 + 同音 + 形音义混 + 简繁差异 · 含口诀
康熙 214 部首 · 85 精选 · 按笔画浏览
前 100 高频字 · 学中文优先顺序 · BCC 语料库
之乎者也矣焉 · 23 高频虚词 · 高考必备
~20 音节 · 4 声分类 · 起名、写诗、避免歧义
SE of mean + proportion
Cohen's d + Hedges' g
r, p-value and 95% CI from paired data
Lakh / crore ↔ million / billion ↔ 万 / 亿
Convert length, weight, temperature, area, volume and speed — instantly, free.
Convert times across ASEAN and global timezones — perfect for remote teams and international meetings.
Convert between KB, MB, GB, TB
Convert speed units instantly — km/h, mph, m/s, knots, Mach and more — with a live conversion table.
Convert data storage units
Calculate the area of any shape — rectangle, circle, triangle, trapezoid and more — with formulas shown.
Convert HEX, RGB, HSL, HSB colours
Calculate percentages, discounts, tips and changes — the fastest percentage tool online.
Generate clean SVG placeholder images for mockups, prototypes and CMS templates. Customise size, colour, text — copy as raw SVG, data URI or download.
Split a PDF or extract specific pages
Rotate PDF pages with live thumbnails
Add page numbers to any PDF
Remove unwanted PDF pages
Drag thumbnails to rearrange a PDF
Strip the fingerprint your PDF leaves
Stamp every page — DRAFT, CONFIDENTIAL, your text
True redaction — bytes removed, not just covered
Shrink PDFs — lossless or aggressive
Pull every word out of a PDF
Word + character + sentence stats
Fill + save any PDF form
Remove photo metadata + GPS
Compare two PDFs line-by-line
Pull embedded images from PDFs
Pull a dominant colour palette from any image
Turn any image into text art
Resize images to exact dimensions or by percentage — free, private, no upload required.
Compress JPG, PNG and WebP images in your browser — no upload, no account, no quality loss you can see.
Convert images to Base64 strings
Convert between JPG, PNG, WebP, GIF
Merge multiple PDFs into one
Convert PDF pages to images
View and remove image EXIF metadata
Add text or image watermarks
Convert screenshots to PDF
Inspect digital signatures in PDF files — signer, certificate, signing time, cryptographic validity. All client-side.
Flesch, FK, Fog, SMOG, CL, ARI
Compare two texts and highlight the differences
Find all valid words from any scrambled letters
Temukan semua kata valid Bahasa Indonesia dari huruf acak — kamus 46.000+ kata KBBI.
拼音查词与成语搜索 — 10万+词条，汉字与拼音双模式
Unscramble huruf menjadi kata — 49,000+ kata DBP, pengesan Kata Dasar
Convert text to any case instantly — UPPER, lower, Title, camelCase, snake_case and more.
Count words, characters, sentences and reading time — free, instant, no signup.
Remove duplicate lines from any text instantly — case-sensitive, trimmed, sorted or unsorted.
Count characters instantly for Twitter, SMS, LinkedIn and more — with live platform limit indicators.
Convert text to Morse code
Reverse text, words, lines and sentences — mirror text for creative and technical uses.
Remove extra spaces, tabs and blank lines from any text — clean messy copy-paste text instantly.
Sort lines alphabetically or by length
Find and replace text instantly — with regex support, case sensitivity and bulk replacements.
Check if a word or phrase is a palindrome
Generate placeholder text instantly — paragraphs, sentences, words or bytes.
Convert Chinese between Simplified, Traditional, Taiwan and Hong Kong variants — all 8 OpenCC modes.
Convert between Mandarin and written Cantonese (嘅、咗、喺、佢) — basic dictionary version.
Convert between Mainland Mandarin (普通话), Malaysian Mandarin (马来西亚华语) and Singaporean Mandarin (Singdarin) — with loanwords, particles, and Cantonese-influenced word order.
Translate between Standard English, Manglish (Malaysian English), and Singlish (Singaporean English) — with lah, lor, leh, makan, paiseh, kiasu, and all the rest.
Convert between Bahasa Indonesia and Bahasa Malaysia — with a False Friends panel that catches words like "pusing", "butuh", and "kereta" that mean different things in each country.
Word count, reading time, Flesch-Kincaid grade level, Gunning-Fog index, and top words — live as you type.
Interactive 8x8 board · full FIDE rules · FEN/PGN export
Algebraic ↔ Long ↔ UCI ↔ ICCF ↔ English Descriptive
50 major openings · ECO codes · main-line PGN + ideas
Wheel of names — pick a winner at random
Split a list of names into balanced random teams
Pick a random date in a range — with working-day filters
Stuck for plans? Get a weekend activity idea
Get a ready-to-go workout by equipment, time, and level
Generate random names for fiction, gaming, projects and baby name inspiration — with gender and origin filters.
Generate truly random numbers, sequences and picks — for games, decisions and statistics.
Flip a virtual coin instantly
Convert between Roman numerals and Arabic numbers instantly — with step-by-step explanation.
Roll any dice combination — D4 to D100, custom dice, multiple rolls and full roll history.
Randomly split people into teams
Calculate your exact age in years, months, days — and find out what day you were born.
Spin a wheel to make decisions
Set a countdown timer or count to a target date — with Pomodoro mode and browser notifications.
A clean, precise online stopwatch with lap tracking — works in any browser, no install needed.
Focus timer with Pomodoro technique
Generate random words for creative writing, games, brainstorming and vocabulary practice — with filters by length and type.
Generate HMAC signatures with SHA-1, SHA-256, SHA-384 or SHA-512. Output as hex, base64 or base64url. All computation in your browser — your secret never leaves this page.
See the impermanent loss on a liquidity position vs just holding
Calculate your crypto profit or loss — enter buy and sell prices to see your exact return on investment.
Convert Bitcoin to SGD, USD, EUR and more — with live rates updated every 60 seconds.
Calculate Ethereum gas fees in ETH and USD — understand what you'll pay before you confirm any transaction.
Convert between Wei, Gwei, ETH
Calculate NFT creator royalty earnings
Generate and verify TOTP codes (RFC 6238) entirely in your browser.
Generate 2048/3072/4096-bit RSA keypairs in PEM and JWK formats, in-browser.
Hash passwords with bcrypt and verify hashes — all client-side, cost-factor adjustable.
zxcvbn-style entropy + crack-time at 4 attack profiles · browser-only
A / AAAA / MX / TXT / CNAME / NS / SOA via Cloudflare DoH (1.1.1.1)
CIDR + mask + broadcast + usable hosts + RFC 1918 detection
Email authentication audit · policy explainer · 9 common DKIM selectors
Expand, compress and subnet any IPv6 address
Turn CIDR notation into the exact IP range it covers
Score a vulnerability with the official CVSS v3.1 base metrics
Memorable, strong passphrases — generated in your browser
What to eat in Singapore — pick a traditional dish at random
What to eat in Malaysia — pick a traditional dish at random
Can't decide what to eat? Pick a dish from 80 world classics
What to eat in Hong Kong — pick a Cantonese dish at random
What to eat in Taiwan — pick a dish at random
What to eat in Macau — Macanese, Cantonese, or Portuguese
What to eat in Thailand — pick a dish (and a spice level)
What to eat in Vietnam — pick a dish at random
Mau makan apa? Pick a traditional Indonesian dish at random
How long jet lag will last — and how to beat it faster
Opening ask, target, walk-away
Side-by-side weighted scoring
WFH vs commute, real dollar terms
Urgent/Important task sorter
Weighted scoring · multi-criteria
Your new pay, the increase, and the real raise after inflation
Weekly and yearly pay with time-and-a-half and double time
Add up clock-in/out times into weekly hours and pay
How much paid leave you’ve earned, used and have left
Estimate retrenchment / severance benefits by tenure
GPA across global grading scales
"What do I need on the final?"
APA / MLA / Chicago / Harvard
Your current course grade — and what you need on what’s left
Grade a test in seconds — percentage, letter and a full chart
The GPA you need from here to hit your goal
Convert CGPA to percentage and back — instantly
Your attendance %, and how many classes you can still miss
See what your education fund grows to — and how much is growth
Add up the real cost of a degree, credit by credit
Annual CO₂e tonnes from 5 categories
Add your appliances, see the bill, the carbon, and where to cut
Size the unit, then see what inverter vs non-inverter really costs
See generation, bill savings and the year your panels pay for themselves
How much rain your roof could catch — and what a tank would deliver
The real carbon cost of a flight — and what it takes to offset it
Compare car, motorbike, MRT, bus, bike — by carbon and by cost
See the carbon in your weekly plate — and the easiest swaps to cut it
Turn your weekly recycling into carbon, energy and landfill saved
How much carbon your trees absorb — and what it takes to offset a footprint
Cubic yards / meters for any pour
Gallons / liters for any room
Tiles + grout for any area
Air conditioner sizing made simple
Volume + chemistry in one tool
Sheets, mud, screws + tape for a room
Cubic yards, tons + bags for any area
Heater size to warm your pool in time
Steps, riser, run + stringer length
Pitch, angle, grade + rafter multiplier
Cement, sand, aggregate + water for a volume
Total rebar weight + cost for a slab
How many rolls of wallpaper you need — pattern repeat included
How much carpet to order — floor area plus waste, in m², ft² and yd²
How many packs of laminate, vinyl or hardwood flooring you need
Posts, panels and rails for a fence run
How many deck boards you need — gaps and waste included
Turf rolls and grass-seed weight for a new lawn
How many bricks (and mortar) for a wall
Board feet of lumber from thickness, width and length
Total R-value and U-value of a layered wall, roof or floor
Gutter length and number of downspouts for a roof run
Scale recipes by serving ratio
Cups, tbsp, ml, grams — any direction
Baker's percentages, 7 style presets
OG/FG → ABV, attenuation, calories
Convert cups, grams, ml, and tablespoons — density-aware
Convert any oven recipe to air-fryer temperature and time
Roasting time, oven temperature and rest time by weight
Swap pan sizes and shapes — and scale the recipe to fit
Hydration and baker’s percentages for any bread formula
Dial in coffee and water for any brew ratio
MPG / L/100km / km/L + trip cost
Reaction + braking by speed
ETRTO comparison + speedo error
Cost to charge + cost per mile vs petrol
True cost of leasing vs financing
Monthly payment, total interest and the payoff curve for your car loan
Work backwards from a budget to the car price you can actually afford
Project your car’s resale value and what it loses each year
The real yearly and monthly cost of running a car — not just the price
Convert hp, kW and torque@rpm — and check power-to-weight
CKD-EPI 2021 race-neutral eGFR
Classic 1972 LDL estimation
AFib stroke risk stratification
Mosteller, Du Bois & Haycock BSA — for dosing and cardiac index
Estimate CrCl for renal drug dosing
1-year major bleed risk on anticoagulation
Pre-test probability for DVT and PE
30-day mortality band + admit decision
Albumin-corrected serum calcium
Metabolic-acidosis screen + albumin correction
Heart-rate-corrected QT with three formulas
Eye + verbal + motor = 3–15 severity
NEC voltage drop %
Ampacity + voltage drop combined
4/5/6 band IEC 60062 decoder
Laminar vs turbulent regime
Conservation of energy fluid
ISO 4.6–12.9, M6–M36
Simply-supported + cantilever
Multi-stage compound trains
Darcy-Weisbach head loss
Tip deflection + slope from point + UDL
Second moment of area, section modulus, radius of gyration
Critical buckling load for slender columns
Head loss + velocity in pressurised water pipes
TDH = static + friction + pressure + velocity head
Wind pressure + force on a flat surface
WHS Handicap Index
Pitcher quality, defense removed
Earned runs per nine innings
The ICC tournament tiebreaker
Scoring efficiency across 2s, 3s + free throws
Goalie SV% and possession Corsi For %
Stat line → points in all three formats
The official 0–158.3 NFL quarterback passer rating
The watts you need to hold a speed — and where they go
Your swim pace per 100m, speed and even-pace splits
Wang 2020 epigenetic formula
AAFP/AAHA life-stage formula
RER + MER for dogs + cats
Monthly premium estimate for dogs + cats
Daily + per-meal portion from calories
Estimate how big your puppy will grow
Gauge the risk if your dog ate chocolate — then call your vet
Estimate your dog’s due date and whelping window
Estimate your pet’s ideal weight from its body condition
How much water your dog or cat should drink a day
V = IR — solve for voltage, current or resistance · 7 curricula
Buffer pH from pKa and the base/acid ratio
Molarity from mass, and dilution volumes
Concentration from absorbance
Limiting reagent, theoretical + percent yield
From percent composition to formula
Solve for pressure, volume, moles or temperature
Remaining amount or half-life from decay
F = ma — solve for force, mass or acceleration · 7 curricula
F = Gm₁m₂/r² — solve for force, mass or distance · 7 curricula
pH ↔ pOH ↔ [H⁺] ↔ [OH⁻] — convert any one · 7 curricula
M = n/V — solve for molarity, moles, volume or mass · 7 curricula
Parse a chemical formula, sum the atomic masses · 7 curricula
ρ = m/V — solve for density, mass or volume · 7 curricula
118 elements, names in your curriculum language · 7 curricula
Monohybrid & dihybrid crosses, instant ratios · 7 curricula
Codon ↔ amino acid lookup + full code table · 7 curricula
KE = ½mv² — solve for energy, mass or velocity · 3 curricula
PE = mgh — solve for energy, mass or height · 3 curricula
p = mv — solve for momentum, mass or velocity · 3 curricula
v = fλ — solve for speed, frequency or wavelength · 3 curricula
n₁sinθ₁ = n₂sinθ₂ — solve for index or angle · 3 curricula
Q = mcΔT — solve for heat, mass, specific heat or ΔT · 3 curricula
Moles ↔ particles ↔ mass · 3 curricula
PV = nRT — solve for pressure, volume, moles or temperature · 3 curricula
M₁V₁ = M₂V₂ — work out a solution dilution · 3 curricula
ΔG = ΔH − TΔS — solve and check spontaneity · 3 curricula
20 amino acids — codes, names, codons · 3 curricula
M = objective × eyepiece — work out magnification · 3 curricula
Solve any of s, u, v, a, t from the equations of motion
E = E° − (RT/nF) ln Q — cell potential at non-standard conditions
Stage time = (cells in stage ÷ total cells) × cell-cycle time
p + q = 1 and p² + 2pq + q² = 1 — genotype frequencies from allele frequencies
Allele frequencies from genotype counts — with a χ² test against Hardy-Weinberg
Pressure + density altitude for takeoff performance
Wind components from runway heading
TAS from CAS, altitude and temperature
Rode length to let out for safe anchoring
Feels-like temperature, hot or cold
Estimate walking time over distance + ascent
Flash-to-bang distance + the 30-30 rule
Sunrise, sunset, golden hour and day length for anywhere
Calories burned hiking — with pack weight, grade and terrain
How muggy will it feel? Dew point from temperature and humidity
A fast, free online calculator
Add, subtract, multiply and divide fractions
Long division with full worked steps
Greatest common divisor and least common multiple
Is it prime? Plus full factorisation
Round to places, sig figs, or nearest 5/10/100
Mean, median, mode, spread, quartiles & outliers
Raise any number to any power
log, ln, log₂ and any custom base
Square root, cube root, any nth root + surds
Solve 2×2 and 3×3 systems with working
Add, multiply, divide and evaluate polynomials
Factor polynomials and find their roots
Find a missing side of a right triangle
Area, circumference, radius, sector & arc
sin, cos, tan, their reciprocals and inverses
Solve any triangle from 3 measurements
Area and perimeter of any 2D shape
Volume and surface area of any solid
Differentiate any function, exactly
Antiderivatives and definite integrals
Evaluate limits, one-sided or at infinity
Determinant, inverse, eigenvalues and more
Dot, cross, magnitude, angle and projection
Arithmetic, polar form, powers and roots
Binary, hex and bitwise arithmetic
Mod, GCD, modular inverse and power
nCr, nPr and factorials for counting
Trig, logs, powers, roots and more
Simplify any ratio to its lowest terms
Solve a : b = c : x for the missing value
Write any number in words
Nth term and sum of an arithmetic or geometric sequence
Simplify an aspect ratio and resize without distortion
How far a measurement is from the true value, as a percentage
Cousin removal, great/grand & in-laws — US/UK/AU/Indian
Pak Long position system + Javanese/Sundanese/Sumatran/Tionghoa
First cousin once removed, second cousin — degree + removal, explained
Boomer, Gen X, Millennial, Gen Z or Alpha?
What blood type can our baby have?
The exact age gap between two people, to the day
How many ancestors do you have, generations back?
How much DNA do relatives share?
Your Chinese zodiac animal, element and yin-yang
Find your star sign, element and dates from your birthday