CAC Payback Period
The number of months it takes for a customer's gross profit to repay the cost of acquiring them. The standard threshold of efficient SaaS growth is under 12 months for SMB, under 18 months for mid-market, under 24 months for enterprise.
CAC Payback Period is the number of months required for a new customer's gross-margin-adjusted recurring revenue to recoup the cost of acquiring them. The formula:
Payback (months) = CAC / (ARPA × gross margin)
Where ARPA is average revenue per account per month, and gross margin is the recurring contribution margin (typically 70–85% for SaaS).
Why payback matters
LTV/CAC is the more famous unit-economics ratio but takes years to verify because LTV requires churn data. Payback period is a near-term check on the same question — can you keep funding growth without raising more cash? A 12-month payback means every $1 spent on sales and marketing returns $1 within a year, which is cash-flow positive on the acquisition cohort.
VCs evaluating SaaS companies treat payback as a faster-than-LTV signal of efficiency, especially for pre-Series B companies where LTV estimates are still noisy.
Benchmarks by segment
- SMB SaaS: under 12 months payback is healthy; under 6 months is best-in-class
- Mid-market SaaS: under 18 months payback is healthy
- Enterprise SaaS: under 24 months payback can still be healthy if NRR is strong (because expansion compounds after payback)
- Consumer subscription: typically under 3 months payback because LTV is short
A payback over 24 months for SMB or 36 months for mid-market usually indicates either inefficient go-to-market or under-priced product.
Related
- CAC — the numerator of the payback formula
- LTV — what payback eventually rolls into
- Unit Economics — the broader framework
See also
- GlossaryCAC
- GlossaryLTV
- GlossaryUnit Economics