CAC Payback Calculator: Months to Recover Acquisition Cost
Work out the CAC payback period — how many months a new customer takes to repay what it cost to acquire them.
Adjust the inputs and select Calculate for a full breakdown.
Compare Common Scenarios
How the numbers shift across typical situations for this calculator:
| Scenario | Months to recover CAC |
|---|---|
| $1,200 CAC · $150/mo | 8 |
| $600 CAC · $50/mo | 12 |
| $5,000 CAC · $400/mo | 12.5 |
| $300 CAC · $75/mo | 4 |
How This Calculator Works
Enter the customer acquisition cost — the total sales and marketing spend to win one customer — and the monthly gross margin that customer generates. The calculator divides one by the other to give the number of months before the customer turns profitable.
The Formula
Recovery Period
Fixed Cost is the upfront amount, Benefit per Period is the recurring gain that pays it back
Worked Example
A customer that costs $1,200 to acquire and produces $150 of monthly gross margin has a CAC payback of 8 months. Only after month eight does that customer start contributing profit rather than repaying acquisition cost.
Key Insight
A short CAC payback frees cash to reinvest in growth sooner and cushions against churn. If customers routinely cancel before the payback month, the acquisition channel is losing money on every sale.
Frequently Asked Questions
What is CAC payback?
It is the number of months a customer takes to generate enough gross margin to repay the cost of acquiring them. After that point, the customer is profitable.
What goes into customer acquisition cost?
All sales and marketing spend attributed to winning a customer — ad spend, salaries, tools, and commissions — divided by the customers that spend produced.
Why use gross margin rather than revenue?
Revenue ignores the cost of serving the customer. Gross margin — revenue minus that cost — is the cash actually available to repay acquisition cost.
What is a healthy CAC payback?
It varies by business and funding, but many subscription businesses aim to recover CAC within roughly a year. Shorter is safer; much longer strains cash flow.
Does this account for churn?
No. It measures time to repay CAC assuming the customer stays. If customers churn before the payback month, the real economics are worse than the figure shown.
Related Calculators
Methodology & Review
The CAC payback is the customer acquisition cost divided by the monthly gross margin per customer. It measures how soon a customer becomes profitable, before any churn or expansion is considered.
Written by Ugo Candido · Last updated May 17, 2026.