Free calculator · 60 seconds

CAC payback calculator.

How long does it take to recover your customer acquisition cost? This calculator gives you the payback in months and tells you whether your unit economics are healthy (under 18 months), at-risk (18-30), or broken (30+). Calibrated for B2B SaaS.

Your inputs
Average yearly revenue per customer at signing
$24K
After cost of delivery. Typical SaaS: 70-85%. Services: 40-60%.
75%
Total S&M spend ÷ new customers in same period. Include rep comp + tools + paid + content.
$18K
Average ACV growth from existing customers in their first year. 0% = no expansion, 30% = strong NRR.
+10%
Payback diagnosis
12 mo
CAC payback period
Year-1 gross profit per customer $18.0K
Monthly gross profit $1.5K
CAC : ACV ratio 0.75
Health tier Healthy
3-year LTV (est.) $59K

Healthy unit economics

How the math works

What\'s behind the calculation

CAC payback (months) = CAC ÷ (ACV × gross margin ÷ 12 × (1 + expansion/2)). Expansion is halved because it ramps over the year rather than landing on day one.

Health tiers: under 12 months = healthy, 12-18 = good, 18-24 = at-risk, 24+ = broken. These are SaaS benchmarks; services businesses can support longer payback if expansion or retention is strong.

3-year LTV (estimated) assumes 90% gross retention and continued expansion. This is a rough estimate — your actual LTV depends on logo churn and net retention dynamics specific to your business.

If your payback is in the at-risk or broken zone, the fix is rarely about cutting CAC — it\'s about ICP refinement, sales motion efficiency, or pricing. See the AI-Native GTM Framework for the operational view.

Related

Related calculators & resources

CAC payback in the at-risk zone?
A Fractional CRO engagement typically tightens payback by 30-50% within 6 months through ICP refinement and sales motion redesign.
See Fractional CRO → Book the AI Audit