CAC Payback Calculator
Calculate simple customer acquisition cost payback period from CAC, monthly revenue and gross margin, with an optional churn-adjusted 12-month contribution view.
Calculate CAC payback period
Estimate how many months of gross-margin contribution are needed to recover customer acquisition cost.
How the CAC Payback Calculator works
CAC payback asks how long gross-margin contribution from a newly acquired customer takes to recover the acquisition cost. The simple formula is CAC ÷ monthly revenue per customer ÷ gross margin percentage. The tool also calculates a 12-month contribution scenario that reduces the surviving customer base by an optional monthly churn assumption.
How to use this cac payback calculator
Enter blended or channel-specific CAC, monthly customer revenue and the gross margin percentage that remains after cost of goods or service delivery. Use the same cohort definition for both CAC and revenue. If you add churn, treat the 12-month result as a simple expected-value scenario rather than a detailed cohort survival model.
How to interpret the result
A shorter payback period means acquisition cash is recovered faster under the entered economics. The monthly contribution result makes the denominator transparent, while the 12-month contribution-to-CAC ratio shows whether one year of expected contribution covers acquisition spend. Neither metric measures lifetime profitability by itself.
Assumptions and limitations
CAC definitions vary: sales salaries, marketing payroll, tools, agency fees and overhead may be included or excluded. Gross margin can also vary by product and customer. The simple payback result assumes stable monthly contribution and does not discount cash flows. Churn, expansion and contraction can materially change realized recovery.
Practical example and workflow
If CAC is 12,000, monthly revenue is 3,000 and gross margin is 75%, monthly contribution is 2,250 and simple payback is about 5.33 months. A growth team can compare that with a higher-CAC channel that produces larger customers instead of judging channels by CAC alone.