How to use this calculator
Enter acquisition spending and customers for one cohort, then monthly revenue, contribution margin and contribution LTV per customer.
Formula and method
CAC = acquisition spend/new customers. Simple payback months = CAC/(monthly revenue×contribution margin). LTV/CAC uses contribution LTV.
Worked example
12,000 spend and 100 new customers gives CAC 120. At 50 monthly revenue and 60% margin, payback is 4 months.
Assumptions and supported scope
Simple undiscounted payback ignores churn, delayed payments, and changes in revenue or margin. Zero contribution cannot recover positive CAC.
Method references
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