CAC and Payback Calculator
Calculate acquisition cost and an approximate gross-profit payback period. Match the costs to the customers they acquired; a reporting-period mismatch can make the result misleading.
How the calculation works
Blended CAC = acquisition spend ÷ new paying customers. Monthly gross profit per customer = monthly revenue per customer × gross margin. Simplified payback = CAC ÷ monthly gross profit per customer.
Worked example
12,000 in acquisition spend divided by 60 new paying customers gives a CAC of 200. Revenue of 100 per customer at an 80% gross margin produces 80 of monthly gross profit and a 2.5-month payback.
Read the limits before using the result
Include the cost categories appropriate to your decision and identify omissions. This simplified model assumes constant revenue and margin and does not model churn, sales-cycle lag, financing or cash collection.
David Skok on SaaS metrics and acquisition economics. See our calculation and research methodology.