About CAC Payback
CAC payback measures how long it takes your SaaS business to recover the cost of acquiring a customer through the gross profit they generate. It’s a useful metric for understanding how efficiently your business turns acquisition spending into growth.
How it’s calculated
CAC payback is calculated by dividing the cost of acquiring a customer by the monthly gross profit that customer generates.
CAC payback = CAC ÷ (Monthly revenue per customer × Gross margin)
For example, if your customer acquisition cost is $1,500, your average monthly revenue per customer is $200, and your gross margin is 85%, your monthly gross profit is $170.
$1,500 ÷ ($200 × 85%) = 8.8 months.
You would recover your acquisition cost in approximately 8.8 months.
Why it matters
A shorter payback period means you recover your acquisition investment sooner, freeing up cash to reinvest in growth. A longer payback period means more capital remains tied up in acquiring customers before it’s recovered.
The right target depends on your business model, growth strategy, available capital, and customer retention. CAC payback is best evaluated alongside customer lifetime value (LTV) to understand whether the profit generated over a customer’s lifetime justifies the acquisition cost.
Assumptions and limitations
This calculator assumes monthly revenue and gross margin remain constant throughout the payback period. It does not account for customer churn, expansion revenue, changes in costs, or the time value of money. If a customer cancels before you recover their acquisition cost, you may not recoup the full investment.