CAC payback period is one of the most important metrics for early-stage SaaS companies. It answers a simple question: how long does it take to earn back what you spent acquiring a customer?
How to calculate CAC payback period
CAC payback (months) = CAC ÷ (MRR per customer × gross margin %)
Example: If you spend $1,200 to acquire a customer who pays $99/month at 75% gross margin:
- Monthly gross profit = $99 × 0.75 = $74.25
- Payback period = $1,200 ÷ $74.25 = 16.2 months
Benchmarks by go-to-market motion
| GTM Motion | Excellent | Good | Concerning |
|---|---|---|---|
| Self-serve / PLG | < 6 months | 6–12 months | > 12 months |
| Inside sales | < 12 months | 12–18 months | > 24 months |
| Field / enterprise | < 18 months | 18–24 months | > 30 months |
Why investors focus on CAC payback
A business with 18-month payback that grows 100% YoY needs to fund 18 months of CAC for every new customer — that's significant working capital. Companies with sub-12-month payback can grow faster without external capital, since each cohort "pays for itself" within the year.
Use the Unit Economics Calculator to calculate your current payback period and model the impact of changing CAC or MRR.