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CAC payback calculator

Acquisition cost divided by the gross profit a customer produces each month. It is the number that decides whether growth funds itself or has to be funded — and how fast you can afford to spend.

CAC payback

2.9 months

Under twelve months: growth largely pays for itself.

Gross profit per customer per month
€72.98
Average customer lifetime
28.6 months
Lifetime value
€2,085
LTV : CAC
9.93×
Share of lifetime spent paying back CAC
10.1%

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The number

Payback decides your speed, LTV:CAC decides your viability

A twelve-month payback with a 3:1 LTV:CAC is a healthy business that grows slowly, because every customer ties up a year of cash before returning any. The same ratio at a five-month payback grows twice as fast on the same money.

Payback = CAC ÷ (ARPA × gross margin)

Getting it right

  • Use gross profit, not revenue. Paying back CAC out of revenue you never keep is not paying it back.
  • Include the salaries of everyone who sells and markets — CAC without people is roughly half the real figure.
  • Annual prepayment shortens the cash payback dramatically even though the accounting payback is unchanged.

Templates that go further

Change the ad budget

Move the spend and watch margin, cash and the runway date move with it, before you change anything in the ad account.

Questions

CAC payback calculator — What people ask about it

What is a good CAC payback period?

Under twelve months is the usual benchmark for a subscription business, and under six is strong. What matters more is whether the payback is shorter than your runway: a fourteen-month payback with nine months of cash is a growth plan you cannot finish.

Why does churn appear in a payback calculation?

It does not affect the payback itself, but it decides whether the customer is still there to reach it. At 3.5% monthly churn the average customer lasts 29 months, so a 14-month payback spends half their life just breaking even.

One number is an average. Your cash moves day by day.

Connect your accounting data and Foreqast keeps this calculation live — with every committed cost on the date it actually lands.