CAC calculator
Work out what each new paying customer costs you, and how many months of gross profit it takes to earn that back.
Results
CAC formulas
- CAC = (marketing spend + sales spend) ÷ new paying customers
- CAC payback = CAC ÷ (ARPU × gross margin), in months
Example
$3,000 of ads and content brings 40 new customers paying $29 a month at an 80% margin: CAC = $75, paid back in 3.2 months.
Benchmarks
| CAC payback | What it means |
|---|---|
| Under 6 months | Excellent: you can scale acquisition from cash flow |
| 6–12 months | Healthy for most small SaaS |
| 12–24 months | Needs low churn or annual plans to work |
| Over 24 months | Acquisition probably loses money |
When you buy a SaaS, ask for the spend and the customers it brought, per channel: a business that grows only through paid ads is worth less than one with organic acquisition. Compare CAC with lifetime value in the LTV calculator.
Frequently asked questions
How do you calculate customer acquisition cost?
CAC = total sales and marketing spend in a period ÷ new paying customers acquired in that period. $3,000 of spend for 40 new customers is a $75 CAC.
What is CAC payback?
The number of months a customer needs to repay its acquisition cost from gross profit: CAC ÷ (ARPU × gross margin). Under 12 months is considered good for small SaaS.
Should I include free or organic customers in CAC?
Blended CAC divides all spend by all new customers, including organic ones. Paid CAC only counts customers from paid channels. Track both: blended CAC flatters a business with strong SEO, paid CAC tells you if ads scale.