Customer lifetime value calculator for SaaS.
Estimate how customer revenue, margin and churn relate to acquisition cost. All formulas are visible — free, no sign-up.
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Steady-state gross-profit estimate. No expansion, cohort variation, discounting or benchmark recommendation. ARPA and churn must both be monthly. LTV = ARPA × margin / churn (fractions); payback = CAC / monthly gross profit.
SaaS metric formulas
Constant inputs, customer/logo churn, gross-profit LTV. Undefined divisions return no estimate.
| Metric | Formula | Unit |
|---|---|---|
| Monthly gross profit | ARPA × gross margin / 100 | USD/customer/month |
| Expected lifetime | 1 / (monthly customer churn / 100) | Months |
| Customer lifetime value | Monthly gross profit / (monthly churn / 100) | USD/customer |
| LTV:CAC | Customer lifetime value / CAC | Ratio |
| CAC payback | CAC / monthly gross profit | Months |
How to use
- Enter monthly ARPA in USD and gross margin percentage.
- Enter monthly customer churn and customer acquisition cost in USD, using the same cohort and period.
- Calculate customer lifetime value, LTV:CAC and payback; inspect assumptions and undefined cases.
Reference documentation
Frequently asked questions
Is this free, and do I need to sign up?
Free, no sign-up. Inputs and results stay in your browser. Analytics record only a tool identifier and action, never your input.
Is this a loan-to-value calculator?
No. It calculates customer lifetime value for SaaS, not mortgage or loan-to-value ratios.
What is the SaaS customer lifetime value formula?
Under constant monthly customer churn, expected lifetime is 1 divided by churn as a fraction. Gross-profit LTV is monthly ARPA × gross margin fraction ÷ monthly customer churn fraction.
What does CAC include?
Use fully loaded acquisition cost per new customer, consistently measured for your chosen cohort and period. Include applicable sales, marketing and acquisition labor costs, not only ad spend.
How is payback calculated?
CAC divided by monthly ARPA × gross margin fraction. The output is months. It ignores expansion and changing margin and does not forecast your actual cash flow.
Can I enter annual churn or net revenue churn?
No. Inputs are monthly customer/logo churn, not net revenue churn. With constant churn, convert annual customer churn to monthly as 1 − (1 − annual churn fraction)^(1/12). Expansion revenue needs a different model.
What happens at zero churn, zero CAC or zero margin?
Zero churn produces no finite lifetime or LTV estimate. Zero CAC makes LTV:CAC undefined. Zero gross profit makes payback undefined. The output uses null with explanations rather than misleading infinite values.
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