How to use this calculator
- Enter customer acquisition cost, monthly revenue per customer, gross margin (%).
- Choose a display currency, then select Calculate. Results also update after a brief pause while you edit.
- Read the result with the assumptions below. Export details or save a second scenario to compare your choices.
Formula and method
Assumptions and limitations
The monthly gross-profit contribution must be positive; include the same cost basis in CAC and margin.
Worked example
With customer acquisition cost = 400, monthly revenue per customer = 100, gross margin (%) = 80, payback period in months is approximately 5.
What the result means
This estimates gross-profit recovery time before cohort churn and cash-collection timing.
Common questions
How should I interpret payback period in months?
This estimates gross-profit recovery time before cohort churn and cash-collection timing.
What should I check before using this result?
The monthly gross-profit contribution must be positive; include the same cost basis in CAC and margin.
Methodology and transparency
Calculation specification reviewed on 2026-10-14. Mathematical implementation is tested against independent reference fixtures. This does not imply review by a licensed financial professional. Read the testing and precision policy.