CAC Payback Period Calculator
Last updated: October 15, 2026
Estimate how many months of gross-margin contribution are needed to recover customer acquisition cost.
Estimated CAC payback period
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- Monthly gross-margin contribution: —
- Annualized contribution after service cost: —
- Contribution as % of CAC per month: —
- Months to recover CAC before expansion: —
On this page
Quick summary: Estimate how many months of gross-margin contribution are needed to recover customer acquisition cost.
Read the complete guide
Updated reference sections in this guide are in English.
What this calculator estimates
Estimate how many months of gross-margin contribution are needed to recover customer acquisition cost.
How to use it
Enter Customer acquisition cost ($); Monthly recurring revenue per customer ($); Gross margin (%); Additional monthly customer service cost ($); Expected monthly expansion revenue ($). Select Calculate to update the results.
How the calculation works
Monthly contribution equals recurring and expansion revenue multiplied by gross margin, less the entered service cost. CAC is divided by that contribution.
Worked example: starting scenario
| Customer acquisition cost ($) | 4200 |
|---|---|
| Monthly recurring revenue per customer ($) | 850 |
| Gross margin (%) | 78 |
| Additional monthly customer service cost ($) | 75 |
| Expected monthly expansion revenue ($) | 35 |
| Estimated CAC payback period | 6.8 months |
|---|---|
| Monthly gross-margin contribution | $615.30 |
| Annualized contribution after service cost | $7,383.60 |
| Contribution as % of CAC per month | 14.65% |
| Months to recover CAC before expansion | 7.1 months |
Important limitations
Cohort churn, billing timing, sales commissions, implementation, expansion, bad debt and attribution can change the actual payback period.