Mortgage Amortization Schedule Calculator
Mortgage amortization schedule calculator. Year-by-year breakdown of every monthly payment into principal + interest, cumulative interest paid, and ending balance. The honest view of total mortgage cost.
Mortgage Amortization Schedule Calculator
Year-by-year amortization schedule
| Year | Principal paid | Interest paid | Cumulative interest | Ending balance |
|---|
How to use the amortization calculator
Enter loan amount
The original loan principal — typically home price minus down payment. A $400K home with $80K down = $320K loan. For refinancing analysis, use your current outstanding balance, not the original loan amount. Doesn't include closing costs (those are paid in cash up-front).
Enter interest rate (%)
Annual fixed rate at origination. For 30-year fixed conventional loans mid-2026, ~6.5-7.5% for prime borrowers. Lower-credit borrowers + FHA loans typically 0.5-1.5% higher. ARMs (adjustable-rate mortgages) start lower but reset — for ARM analysis, use the projected average rate over your hold period, not the teaser rate.
Choose term (years)
30 years: lowest monthly payment, most lifetime interest (~$450K of interest on a $320K loan @ 7%). 15 years: higher monthly payment (~50% more), much less interest (~$200K on the same loan). 20 years: middle ground, less common. 15-year fixed rates are typically 0.4-0.7% below 30-year rates, compounding the interest savings.
Read monthly P&I + total interest
Three headline numbers. Monthly P&I: the fixed principal + interest portion of your payment (excludes taxes, insurance, HOA, PMI). Total interest paid: lifetime interest cost — usually shockingly large for 30-year loans. Total of all payments: principal + total interest. For a typical 30-yr @ 7%, you pay roughly 2.4× the loan amount over the full term.
Study the year-by-year breakdown
The amortization table shows annual aggregates: how much principal vs interest you pay each year. Watch the "crossover" year — when annual principal first exceeds annual interest. For 30-yr @ 7%, that's around year 21. Until then, most of your monthly cheque to the lender is interest. The cumulative interest column tracks running total — useful for tracking your "real cost" at any point during the loan.
Amortization — the schedule that shows you exactly where your money goes
Amortization is the process of gradually paying off debt through scheduled equal periodic payments. For a fixed-rate mortgage, every monthly payment is the same total dollar amount — but how that payment splits between principal and interest shifts dramatically over the life of the loan. Early payments are mostly interest; later payments are mostly principal. This isn\'t a quirk; it\'s the consequence of interest accruing on the outstanding balance. When the balance is high (early in the loan), interest dominates. As the balance shrinks (later), interest shrinks too — and more of each payment goes to principal. The amortization schedule makes this visible month by month, year by year. It\'s also the single most sobering view of total mortgage cost most borrowers ever see.
Why the front-loaded interest matters
For a 30-year mortgage at 7%, the first month\'s payment is ~58% interest, 42% principal. By year 10, the split is roughly 50/50. The principal-dominant crossover — when annual principal first exceeds annual interest — comes around year 21. By year 30, the final payment is 99% principal, 1% interest. This front-loading has two practical implications. (1) Early-year extra payments are extraordinarily efficient: every $1,000 extra principal in year 1 saves you the interest on $1,000 for 29 more years — easily $1,500-$2,000 in lifetime interest. The same $1,000 in year 25 saves only $200-$300. (2) Selling early means less equity than people expect: 5 years into a 30-year @ 7%, you\'ve paid off only ~8% of the loan principal despite making 60 monthly payments. Most of that money went to interest.
Five years into a 30-year mortgage @ 7%, you\'ve made 60 payments — but paid off only ~8% of the principal. The other 92% of payments went to interest. The amortization curve is the most expensive thing nobody explains to first-time buyers.
30 vs 15 vs 20 — the real cost of optionality
A $320K loan at 7% over 30 years costs $447K in lifetime interest — total payments $767K. The same loan over 15 years costs $198K in interest — total $518K. Saving $250K over the life of the loan. The catch: monthly payment jumps from $2,129 (30-yr) to $2,876 (15-yr) — a 35% increase. Whether 15 or 30 makes sense depends on (a) cash-flow tolerance for the higher payment, (b) opportunity cost — if you can earn >7% after-tax on alternative investments, the lower 30-year payment + invest-the-difference may win, (c) optionality — a 30-year gives flexibility to pay extra principal later or use the cash elsewhere. Most personal-finance authorities recommend 15-year if cash flow permits; the math is brutal in its favour.
ASEAN context — mortgage amortization basics
The amortization math is identical worldwide — French-style equal-installment amortization is universal. What differs is term length and rate environment. Singapore: HDB loans typically 25-year terms; bank loans up to 35 years with restrictions on age + LTV. Rates pegged to SORA or fixed via SIBOR-replacement benchmarks. Malaysia: typical 25-30 year terms, BR-pegged variable rates. Indonesia: KPR (Kredit Pemilikan Rumah) typically 15-20 year terms, BI-7DRR linked. Asian borrowers often see effective rates 1-3% higher than US prime borrowers due to lower benchmark rate environments not fully translating to consumer mortgage rates. The amortization curve\'s general shape — front-loaded interest, gradual principal-dominant transition — is universal.
10 Things to Know About Mortgage Amortization
Equal payments, unequal splits. Every monthly payment is the same total, but principal/interest split shifts dramatically over the loan.
French amortization — used worldwide since the mid-19th century. The 1934 US National Housing Act standardised it for residential mortgages.
For a 30-yr @ 7%, the principal-dominant crossover — when annual principal first exceeds interest — comes around year 21.
Total interest over 30-yr @ 7% on a $320K loan: ~$447K. That\'s 140% of the original loan amount, paid in interest alone.
5 years in, you\'ve barely dented principal. 60 payments on a 30-yr @ 7% paid off only ~8% of the loan. The rest was interest.
Early extra payments are gold. $1K extra principal in year 1 saves 29 years of interest on that $1K — ~$1,500-$2,000 lifetime savings.
15-year vs 30-year: 35% higher monthly payment, but ~55% less lifetime interest. Hugely favourable if cash flow allows.
Some loans "recast" when you pay a large lump sum — re-amortizing the remaining balance at a lower monthly payment.
Bi-weekly payments (every two weeks) = 26 half-payments = 13 full monthly payments per year. Shaves 4-6 years off a 30-yr loan.
Tax-wise: mortgage interest is deductible up to $750K loan (US, 2017 TCJA reform). Front-loaded interest = front-loaded tax benefit.
Frequently asked questions
-
Because interest accrues on the outstanding balance. In month 1, your balance is the full loan amount, so the interest portion (balance × monthly rate) is large. Each subsequent month, balance shrinks slightly, so interest shrinks slightly — and more of each payment goes to principal. It\'s not "unfair" or a lender trick; it\'s the necessary consequence of compounding interest on the unpaid balance. Some borrowers don\'t realise it until they\'re 5 years in and barely above 90% LTV. The amortization table makes it visible.
-
Mathematically, yes — every extra dollar of principal eliminates the interest you\'d pay on that dollar for the rest of the loan. The earlier in the loan, the more interest you save (29 years vs 5 years of compounding). However: compare to the after-tax return on alternative investments. If your mortgage rate is 7% and you can reliably earn 9-10% after-tax in a 401(k) or index fund, investing the extra cash beats prepaying. If your mortgage rate is 7% and your only alternative is a 5% high-yield savings account, prepaying wins. Behavioural angle: prepaying is "guaranteed return"; investing has variance. Most personal-finance authorities recommend maxing tax-advantaged retirement accounts first, then prepaying mortgage with anything left.
-
The basic mortgage calculator just gives you the monthly P&I. This tool shows the full lifecycle: year-by-year principal vs interest split, cumulative interest paid, and ending balance every year. The amortization view is what reveals the front-loaded interest, the principal-dominant crossover, and the "5 years in, only 8% paid off" reality. Both tools are useful for different stages: monthly P&I for affordability shopping, amortization schedule for understanding what you\'re really signing up for.
-
Not directly — this calculator assumes a constant interest rate. ARMs have an initial fixed period (5, 7, or 10 years typical) then reset annually based on an index + margin. For ARM analysis, you can model the fixed period accurately and then run a separate amortization for each adjustment period using projected reset rates. Most US ARMs are now SOFR-indexed (replaced LIBOR in 2023). Pre-2010 ARMs were typically LIBOR-indexed; post-2010 SOFR. The amortization math is identical; only the rate input changes period-by-period.
-
Recasting (or "re-amortization") is when you make a lump-sum principal payment and the lender re-amortizes the remaining balance over the original remaining term, producing a lower monthly payment. Differs from refinancing: same interest rate, same term-end, just spreads the smaller balance over the remaining months. Typically costs $200-$500 for the lender to recast. Useful if you receive a windfall (inheritance, bonus, stock sale) and want lower monthly payments without going through full refinance underwriting. Most conventional loans allow one recast per year; some only after specific minimum lump sums ($5K-$10K). Not all lenders offer it.
-
Because of front-loaded interest. On a 30-year @ 7%, you\'ve made 60 monthly payments totalling ~$128K, but only ~$25K went to principal — the other $103K went to interest. Loan balance dropped from $320K to about $295K. This is the most uncomfortable revelation in mortgage math, and one of the strongest arguments for either (a) 15-year terms if cash flow allows, (b) extra principal payments in early years, or (c) at least understanding the trade-off before committing to a 30-year loan. The amortization table makes the curve unavoidable.
-
In the US, yes — but with limits since the 2017 Tax Cuts and Jobs Act. Acquisition debt up to $750K ($375K married filing separately) on primary + one second home: interest is deductible if you itemize. Pre-TCJA debt limit was $1M and grandfathered for old loans. The standard deduction increase under TCJA ($14,600 single / $29,200 married 2024) means most middle-class homeowners no longer itemize — only about 10% of US tax filers take the mortgage interest deduction post-TCJA, down from ~30% pre-TCJA. The front-loaded interest in early years is when this deduction matters most; consult a tax professional for your specific situation.
-
The math is exact — standard French amortization, used by every US mortgage lender since the 1930s. Real-world variations: (1) some lenders use actual/360 day-count convention vs actual/365 — produces tiny month-to-month variation, (2) tax/insurance escrow can change escrow payments separately from P&I, (3) ARMs reset rates periodically, (4) extra payments shorten the schedule (use the extra-payment calculator). For a fixed-rate loan with no extras, this calculator matches what your servicer\'s statement will show, dollar-for-dollar, to within rounding.
-
No. Loan amount, rate, term — every input stays in your browser. The full month-by-month amortization computation runs as client-side JavaScript. Open DevTools → Network when you click Build and you\'ll see zero outbound requests. Safe for confidential financial planning.
-
FNMA Selling Guide (selling-guide.fanniemae.com) for standard US mortgage underwriting. Consumer Financial Protection Bureau (consumerfinance.gov/owning-a-home/) for unbiased mortgage education. HUD Handbook 4000.1 for FHA loan rules. For ASEAN: MAS Singapore on housing finance, BNM Malaysia on mortgage regulations. The textbook reference: Brueggeman & Fisher\'s "Real Estate Finance and Investments" — the standard university-level mortgage finance text.
Related News
You may be interested in these recent stories from our newsroom.
-
Snowflake jumps 36 per cent in a day on an earnings beat and a US$6 billion AWS chip deal
Snowflake had its best day as a public company on 28 May, closing up 36 per cent after a clean first-quarter beat and a five-year, US$6 bill...
-
MAS Scraps Mandatory Financial Advice for Most Complex Product Buyers in Retail Shake-Up
Singapore retail investors buying structured notes, derivatives and investment-linked policies will no longer need mandatory financial advic...
-
SEC Rewrites Float Rules, PSE Moves to Implement Them — Clearing the Path for GCash's USD 1B Philippine IPO
The SEC lowered the public float floor for large Philippine issuers in February 2026. The PSE followed with a consultation paper in April. T...
75 more free tools
Calculators, converters, security tools — no signup.