CAC Payback Period Calculator

Until a customer clears their CAC, you're financing growth from cash, which is why shorter wins. Under 12 months is generally considered strong for SMB-focused SaaS; enterprise businesses often tolerate 18 to 24 months on the strength of longer contracts and lower churn. And if payback runs longer than the average customer lifetime, the acquisition cost never comes back at all. Fix churn or pricing before scaling spend.

Track acquisition spend and subscription revenue in a Ferra table and payback by channel or by plan becomes a question, not an export.

It needs your CAC, what a customer pays monthly, and your gross margin. Revenue gets converted to gross profit first; then the calculator counts how many months of that profit it takes to cover the acquisition cost.

Convert revenue to gross profit before anything else: monthly revenue per customer times gross margin. Then divide CAC by the result. Say CAC is $900, customers pay $150 a month, and gross margin is 80%: monthly gross profit is $150 × 0.80 = $120.

Payback = $900 / $120 = 7.5 months. For the first seven and a half months, a new customer is repaying their own acquisition cost; everything after is contribution. The figure doubles as a churn-risk lens, because the longer payback runs, the more customers cancel before they've ever paid for themselves.

Skipping the margin step makes payback look better than it is: divide CAC by raw revenue and the answer reads 20-30% faster than reality at typical SaaS margins. Billing is the other trap. Annual prepay is great for cash flow, but the calculation still takes one-twelfth of the annual price, never the invoice amount.

Within 12 months is the standard SaaS benchmark. Under 6 months is excellent, and 12-18 months is common for companies selling to larger customers. Retention sets the tolerance: enterprise businesses with very low churn can afford 18-24 months, because customers reliably stay long enough to repay.

Read payback as a cash and risk metric, not a profitability one. Run long, and acquisition eats cash for a year or more before returning it: growth has to be financed. Run short, and the same dollars recycle into new customers several times a year. That's why payback, more than LTV:CAC, sets how fast you can afford to grow.

Payback shortens from either end: a smaller cost to recover, or faster gross profit doing the recovering.