Metric
CAC Payback Period
The number of months it takes for a customer to recoup their customer acquisition cost.
CAC Payback Period = CAC / (average monthly gross profit per customer). In 2021 the B2B SaaS median was 11 months; in 2026 it sits at 18 months per Proven SaaS.
VCs in 2026 typically demand < 12 months for good term sheets. Above 18 months, companies get lower valuations or no round at all. It's one of the top-4 metrics in VC diligence alongside Burn Multiple, Magic Number, and Rule of 40.