LTV:CAC Ratio Calculator
Compute LTV:CAC ratio, customer lifetime, and CAC payback period for any SaaS business. Industry benchmark: 3x+ is healthy, sub-1 means you are bleeding cash.
LTV:CAC Ratio Calculator
Revenue per customer
Churn + acquisition cost
LTV swing at different monthly churn rates
How to use the LTV:CAC Ratio Calculator
Pull your true ARPC and gross margin
ARPC = MRR ÷ paying customers (not signups, not free-trial users — paying). For annual plans, divide annual contract value by 12. Gross margin is net of hosting, payment processor fees, customer support, and any cost-of-delivery — not sales and marketing. If your figure is far below the software norm, check that you are not netting sales and marketing out of it — that belongs in CAC, not gross margin.
Use monthly customer churn — not revenue churn
This calculator uses customer (logo) churn for lifetime calculation. If you have negative net revenue churn (expansion exceeds contraction), customer-churn LTV is the conservative floor — your actual LTV is higher. Churn differs enormously by segment — self-serve SMB products lose customers far faster than enterprise contracts — so use your own cohort data. If you do not yet have 12 months of it, take your best estimate and stress-test it with the scenario table.
Compute fully-loaded CAC, not just paid-ad spend
CAC must include all sales and marketing costs for the period — salaries, ad spend, content, sales tools, demo infrastructure, BDR commissions — divided by new paying customers acquired in that same period. Counting only paid ads understates CAC badly. Use the fully-loaded number; it is the one your investors will compute on your behalf.
Read the ratio against the 3x rule
The verdict band tells you where you sit: bleeding (<1), sub-par (1–3), healthy (3–5), or exceptional (5+). Then look at the scenario table — it shows your LTV at six different churn rates. If your ratio is "healthy" only because you used optimistic 1% churn, the table reveals the risk. Aim to be healthy across realistic churn scenarios, not just the best case.
LTV:CAC — the single number that decides whether a SaaS business is real
LTV:CAC is the canonical health metric of subscription businesses. It answers one question with brutal clarity: for every dollar you spend acquiring a customer, how many dollars of contribution margin do you eventually get back? If the answer is less than one, you are losing money on every customer and growth makes the problem worse, not better. If the answer is one to three, you cover the acquisition cost but have no headroom — no margin for marketing inefficiency, no contribution to fund growth, and no buffer when churn ticks up. Three or more is the canonical "fundable SaaS" band. Five or more often indicates the business is under-investing in growth and leaving market share on the table. The threshold comes from David Skok's SaaS Metrics 2.0 on forEntrepreneurs (Matrix Partners): the best SaaS businesses have LTV:CAC above 3 — sometimes as high as 7 or 8 — and recover CAC in under 12 months.
Why exactly 3x — not 2x, not 4x
The 3x rule decomposes cleanly. The first 1x covers the cost of acquiring the customer — you broke even. The second 1x is buffer for marketing inefficiency: not every dollar of CAC actually produces a customer, some acquisition channels degrade as you scale them, and some customers churn early. The third 1x is genuine value creation — contribution that funds product development, headcount expansion, and the next round of growth investment. Below 3x there is no third dollar, which means the business has no engine to fund itself from operating cash. It can still grow if investors keep injecting capital, but the unit economics do not work without that subsidy. Below 1x — the "bleeding" band — even the first dollar is missing. The business is paying to acquire customers who will never collectively return the acquisition cost. Scaling makes the deficit larger. This is a kill-or-fix signal, not a growth signal.
LTV:CAC below 3 says you are paying to acquire customers but not earning enough to scale. Below 1 says you are literally lighting cash on fire — every new sale deepens the hole.
Gross LTV vs net contribution LTV — only the latter is meaningful
A common mistake is computing LTV as ARPC × lifetime — gross revenue times customer lifetime, ignoring margin. This always overstates the true number, by exactly (1 ÷ gross margin) − 1: 25% at an 80% margin, 43% at 70%. The honest formula multiplies ARPC by the gross margin to get monthly contribution, then by customer lifetime. A $100/month customer at 80% gross margin and 33-month lifetime produces $2,640 in net contribution LTV — not $3,300 in gross LTV. The ratio against CAC must use net contribution; otherwise you flatter the business by 25% on a single accounting choice. For more rigorous valuations, sophisticated operators also discount future contribution back to present value (NPV-style LTV) using a discount rate of 10–15%, or compute cohort-based LTV directly from observed cohort retention curves rather than assuming geometric decay. Both refinements typically lower the number — never raise it.
The ASEAN SaaS angle
Regional SaaS faces a structural headwind on LTV:CAC: smaller addressable markets mean less product-led pull and more outbound sales effort per customer, while talent and advertising costs are set globally. A business selling into Singapore or Malaysia alone therefore has less room than a US peer to let unit economics drift and fix them later on a larger market. The practical response is the same set of levers the ratio decomposes into — a higher ARPC (often by moving up-market earlier), a lower CAC through product-led acquisition, and a relentless focus on churn from year one. The math is the same; the margin for error is smaller.
Three jobs for every acquisition dollar — the 3× rule, and where it breaks
The 3x rule comes from David Skok's SaaS Metrics 2.0 on forEntrepreneurs (Matrix Partners): "the best SaaS businesses have a LTV to CAC ratio that is higher than 3, sometimes as high as 7 or 8."
LTV is non-linear in churn. Halving monthly churn from 4% to 2% doubles customer lifetime from 25 to 50 months — and doubles LTV. Small churn improvements compound enormously.
Gross LTV ≠ net contribution LTV. Using revenue without margin overstates LTV by (1 ÷ gross margin) − 1 — 25% at an 80% margin. Only contribution-margin LTV belongs in the ratio.
The CAC payback period is the cash-flow companion to LTV:CAC. Skok's second guideline is to recover CAC in under 12 months; beyond that, profitability is "anemic" and growth has to be funded from outside.
A ratio above 5x often means under-investment in growth, not exceptional product-market fit. Competitors will catch up; spend the surplus on CAC while the math still works.
Negative net revenue churn (expansion > contraction) means customer-lifetime LTV underestimates the truth — Skok's worked example shows a business with 3% negative churn reaching more than three times the revenue of one with positive churn over the same period.
Skok's own case study: HubSpot improved its LTV:CAC over five consecutive quarters by working each component — ARPC, margin, churn and CAC — separately, which is exactly what the scenario table here lets you rehearse.
Skok found a direct channel at 1.5x and a partner channel at 5x inside the same company — segment your ratio by channel and segment before judging the blended number.
The 1/churn formula assumes geometric churn decay (constant monthly probability). Cohort-based LTV — measured directly from observed retention curves — is more accurate but requires 12+ months of data.
NPV-style LTV applies a discount rate (typically 10–15%) to future contribution, recognising that a dollar received in month 36 is worth less than a dollar today. Always lowers the ratio versus the simple formula.
Frequently Asked Questions
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The 3x rule decomposes into three jobs each dollar must do. The first dollar covers the cost of acquiring the customer (break-even). The second dollar is buffer for marketing inefficiency — not every channel scales linearly and some customers churn early. The third dollar is genuine value creation that funds growth from operating cash. Below 3x the business has no third dollar, meaning growth must be subsidised by investor capital indefinitely. The threshold is David Skok's (Matrix Partners), from his SaaS Metrics 2.0 guide on forEntrepreneurs, paired with a second guideline: recover CAC in under 12 months.
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Below 1 means every customer costs more to acquire than they will ever pay back in contribution margin over their lifetime. You are literally losing money on every sale. Scaling makes the loss bigger, not smaller — the opposite of how growth normally works. Either CAC must fall, churn must fall, or pricing must rise dramatically. A business stuck below 1x is not a "needs to scale" problem; it is a "needs a different model" problem.
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Always contribution margin LTV. Gross revenue LTV ignores cost of delivery (hosting, support, payment processing) and inflates the ratio by exactly (1 ÷ gross margin) − 1 — 25% at an 80% margin, 43% at 70%. The honest formula is ARPC × gross margin × customer lifetime. Investors will compute the contribution version on your behalf, so flatter numbers in your pitch deck only set you up for an embarrassing diligence conversation.
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LTV:CAC measures eventual return per acquisition dollar — a profitability metric. CAC payback measures how fast the cash comes back — a liquidity metric. A company can have a healthy 4x LTV:CAC but a 30-month payback period, meaning growth ties up cash for years. Skok's guideline is payback under 12 months; anything beyond 24 requires external funding to scale.
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Two interpretations. (1) Exceptional product-market fit with low churn and viral acquisition — congratulations, you have one of the rare businesses. (2) More commonly, you are under-investing in growth. Your acquisition channels still work but you are not spending enough on them. Competitors will catch up; the window to grow aggressively while the math is favourable closes quickly. Reinvest the surplus into CAC before someone else does.
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Yes — fully-loaded CAC includes all sales and marketing costs: ad spend, BDR/AE salaries and commissions, marketing team headcount, content production, demo infrastructure, sales tools. Divide the total period cost by new paying customers acquired in that period. Founders who count only paid-ad CAC understate the true number badly. Investors will always compute the fully-loaded version.
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If your expansion revenue exceeds contraction/churn, customer-churn-based LTV understates the truth. The simple 1/churn formula assumes flat ARPC over the customer lifetime; if existing customers expand spending over time, real LTV is higher. The conservative approach is to compute customer-churn LTV as a floor, then separately model net revenue retention (NRR) on top. Top-quartile SaaS targets NRR above 120%, which roughly doubles effective LTV versus the customer-churn floor.
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Smaller addressable markets give less room to grow into unit-economics drift later. A US SaaS can hit 3x today and still have years of TAM expansion runway. An ASEAN SaaS often cannot — the market caps out faster, so the business must be more efficient at the start. Regional investors therefore tend to weight the ratio's trajectory and its components — especially churn — more heavily than a US peer at the same stage, particularly for businesses whose primary market is Singapore, Malaysia or Indonesia alone.
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The 1/churn formula assumes geometric (constant monthly probability) churn — customers leave at the same rate every month. In reality, early-tenure customers churn faster than long-tenure ones. Cohort-based LTV measures the actual cumulative contribution from each acquisition cohort over time, then projects the curve forward. It is more accurate but requires 12+ months of cohort data. For pre-Series A businesses, the simple formula is good enough; for growth-stage businesses raising on unit economics, cohort LTV is the standard.
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No. All calculation happens entirely in your browser via JavaScript — no server, no analytics on the inputs, nothing sent over the network. Open DevTools → Network and watch — there is zero outbound traffic from the calculator.
Method & sources
How it computes
Monthly contribution = ARPC × gross margin; customer lifetime (months) = 1 ÷ monthly churn; LTV = monthly contribution × lifetime; LTV:CAC = LTV ÷ CAC; CAC payback (months) = CAC ÷ monthly contribution. Bands: < 1 bleeding, 1–3 sub-par, 3–5 healthy, ≥ 5 exceptional; payback judged against the user's target (default 12 months).
What this tool implements
- David Skok's SaaS Metrics 2.0 guidelines: LTV:CAC > 3 and CAC recovered in under 12 months
- Contribution-margin LTV (ARPC × gross margin), not gross-revenue LTV; gross LTV overstates by (1 ÷ GM) − 1
- Geometric (constant) churn assumption, lifetime = 1 ÷ churn; no discounting of future contribution (stated on page)
- Segment hints and industry percentages removed — inputs are the user's own cohort data
Sources
- Skok D. SaaS Metrics 2.0 — A Guide to Measuring and Improving What Matters. forEntrepreneurs (Matrix Partners). https://www.forentrepreneurs.com/saas-metrics-2/
- Skok D. SaaS Metrics 2.0 — Detailed Definitions (LTV, CAC, churn). forEntrepreneurs. https://www.forentrepreneurs.com/saas-metrics-2-definitions-2/
What can make this go out of date
- none at runtime
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