CAC Payback Period
MetricCAC payback period is the number of months required for a customer's cumulative gross profit to equal their initial acquisition cost.
What is Payback period, in plain English?
Think of CAC Payback as the time it takes to break even on an individual customer. If you spent $120 to acquire a subscriber and they generate $20 in profit each month, it takes 6 months before that customer stops being an expense and starts generating net profit.
How do you calculate Payback period?
Payback Period (months) = CAC ÷ (Monthly Revenue per Customer × Gross Margin %)
Payback period example
CAC is $300, average monthly subscription revenue is $50, and gross margin is 80% ($40 monthly profit). Payback Period = $300 ÷ $40 = 7.5 months.
Common Payback period mistakes
Dividing CAC by raw revenue instead of gross margin is a dangerous error. You haven't paid back acquisition costs until the actual profit (after server, payment, and support costs) covers the CAC.
What is a good Payback period?
Shorter is safer. Many subscription businesses aim to recover CAC within about 12 months, while direct-to-consumer brands with weak repeat purchase often need the first order to pay it back. The real ceiling is set by your cash: payback has to be shorter than the time your working capital can fund acquisition.
Payback period FAQs
How do you calculate CAC payback period?
Divide CAC by the gross profit a customer generates per month. A $120 CAC with $40 of monthly revenue at a 50% gross margin pays back in 120 ÷ 20 = 6 months. For repeat-purchase brands, read it off a cohort payback curve: the month cumulative gross profit per customer crosses CAC.
What is the difference between payback period and LTV:CAC?
LTV:CAC says whether a customer is worth acquiring over their lifetime; payback says how long your cash is tied up before you get it back. A business can have a healthy LTV:CAC and still run out of cash if payback is long, so payback is usually the binding budget constraint.
Why calculate payback on gross margin instead of revenue?
Because revenue isn't yours to keep: product, fulfilment and payment costs come out first. Computing payback on revenue makes it look several times faster than it really is and leads to overspending on acquisition.
Last reviewed October 3, 2026.