CAC Payback Period
Months = CAC / (ARPU × gross margin). Time to recover acquisition cost.
Result
Payback period
5.3 months
Excellent (≤6 mo)
- CAC$200
- ARPU monthly$50.00
- Gross margin75.0%
- Monthly contribution$37.50
- Payback months5.33
- TierExcellent (≤6 mo)
Step-by-step
- Monthly contribution = ARPU × GM = 50 × 0.75 = $37.50.
- Payback = CAC / monthly contribution = 200 / 37.50 = 5.33 months.
How to use this calculator
- Enter CAC + ARPU + gross margin.
About this calculator
CAC payback period = months to recover the customer acquisition cost via gross-margin-adjusted recurring revenue. Best-in-class SaaS: <12 months. 12-24 months acceptable. >24 months = burning cash on growth. PMM math: CAC payback = CAC / (ARPU × gross margin). Used to gauge cash efficiency, especially for venture-funded startups burning toward profitability. Source: David Skok SaaS metrics framework.
Frequently asked
Pure revenue includes CoGS. GM-adjusted shows actual cash you can use to recoup CAC.
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Churn Rate Calculator
Monthly churn = customers lost / start customers. Annualized: 1 − (1−monthly)^12.
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Contribution Margin
CM = Revenue − Variable Costs. CM ratio = CM / Revenue.
MRR / ARR Growth Projection
MRR with monthly growth + churn → 12-month projection. ARR = MRR × 12.
CAC vs LTV Ratio
LTV / CAC ratio. Healthy SaaS: 3:1+; under 1:1 burns money.