CAC Payback Calculator
Find how many months of gross profit it takes to earn back what you spent to win a customer.
Quick answer
CAC payback is the number of months of gross profit needed to recover acquisition cost: payback months = CAC / (ARPA x gross margin), where ARPA is average monthly revenue per account.
CAC Payback Calculator
CAC Payback
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Monthly Gross Profit per Customer
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CAC
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Cumulative Position by Month
| Month | Cumulative gross profit (₹) | Net of CAC (₹) |
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Assumptions & method
- Payback months = CAC ÷ (ARPA × gross margin). Monthly gross profit per customer = ARPA × gross margin.
- Revenue is assumed constant from month 1, with the full month's margin earned each month.
- Churn, expansion, discounts and the time value of money are not modelled.
- The chart extends to about 1.5× the payback period (at least 12 and at most 60 months).
- CAC, ARPA and margin should describe the same customer segment.
Results are estimates based on the figures you enter. They are not guarantees and not financial advice.
Why payback period matters
CAC payback answers a cash question: how long until a new customer has returned the money spent to acquire them? It divides acquisition cost by the monthly gross profit per customer, which is revenue per account multiplied by gross margin. Short paybacks let you recycle cash into more growth quickly, while long paybacks require more funding to scale and carry more risk if customers leave before they have paid back. The chart plots cumulative gross profit against the acquisition cost, and the point where the lines cross is the payback month. It is a simple model with constant revenue and no churn.