CAC alone is a misleading metric. CAC payback (how many months until a customer pays back the cost to acquire them) is the one your CFO cares about. This calculator builds it from first principles — with the trade-offs visible.
We treat all paid spend (search, social, ABM, video, programmatic) as part of CAC. A "media-only CAC" without team and tooling is a misleading number; this calculator already includes the realistic blend.
Monthly gross profit is ACV × Gross Margin ÷ 12. Most B2B SaaS comps use this method. Reference: Bessemer's "Top 10 Laws of Cloud" payback definition.
For enterprise B2B SaaS with NRR > 100%, 3.5 years is a reasonable median. For SMB segments, halve it. For best-in-class enterprise (NRR > 130%), double it.
For a real CAC payback model, you also need cohort retention curves, the time-to-revenue offset, sales overhead loaded on top, and channel attribution. We do all four in a 90-minute working session with paying clients.