What is CAC payback period?
CAC payback period is the number of months it takes to recover your customer acquisition cost from the gross profit a customer generates. A 7.5 month payback means a customer covers what you spent winning them in seven and a half months.
It is the cash-speed read on acquisition. LTV:CAC tells you whether a customer is worth winning. Payback tells you how long your cash is tied up before they pay it back.
The CAC payback formula.
CAC payback period = CAC divided by monthly gross profit per customer. Monthly gross profit is revenue per account times gross margin. So a 6,000 dollar CAC against 800 dollars of monthly gross profit is a 7.5 month payback.
The simple mode divides CAC by monthly revenue instead of gross profit. It is quicker but optimistic, because it ignores the cost of serving the customer. Use the margin version for a number you can take to a board. If you are unsure of your inputs, the CAC calculator works CAC out first.
A worked example.
A customer costs 6,000 dollars to acquire and pays 1,000 dollars a month at an 80% gross margin. Monthly gross profit is 800 dollars. Payback is 6,000 divided by 800, which is 7.5 months.
What is a good CAC payback period?
Under 12 months is the benchmark most B2B SaaS aims for, and under 6 months is strong. Between 12 and 18 is workable but slow, and ties up more cash. Beyond 18 months, payback becomes a real risk unless you are well funded, because every new customer locks up cash for a long time before returning it.
Payback and cash are linked. A long payback with a short runway is dangerous, because you are spending money today that will not come back for over a year. Read payback alongside your LTV:CAC ratio: a healthy ratio with a slow payback still strains cash.
How to improve your CAC payback.
Two levers. Lower CAC, or raise the monthly gross profit per customer through pricing, margin, or faster expansion. Most teams focus on the first.
The structural way to lower CAC is a channel that does not charge per customer. Organic search keeps acquiring customers after the content is published, which lowers blended CAC and shortens payback over time. See how we lower blended CAC with organic search, or look at the Workwize numbers, where organic became the lowest-cost pipeline channel.