How long it takes for the gross profit a customer brings to cover what it cost to win them.
Formula
CAC payback (months) = CAC ÷ average monthly gross profit per customer
Example
Meera's CAC is ₹750. A customer brings ₹4,200 of gross profit over 12 months, or ₹350 a month. Her payback period is ₹750 ÷ ₹350 = 2.14 months.
How you'll hear it
“Payback is just over two months, so we can fund growth from our own cash flow.”
What it helps you decide
How fast you can grow without running out of cash. A long payback means you need money in hand, or a loan, to fund each new customer until they repay.
Where people misread it
People treat a good LTV:CAC as permission to spend, without checking how long the money is locked up. The average formula also hides timing: in a business with large first orders, much of the payback happens on day one, and in a subscription it is spread evenly.
The story
Meera's normal campaigns win customers at ₹750 each. Her freelancer wants to try a festive influencer campaign that would bring in more customers at about ₹1,800 each. LTV:CAC would still be 4,200 ÷ 1,800 = 2.33. Not great, but positive.
| Monthly gross profit per customer (₹4,200 ÷ 12) | ₹350 |
| Normal campaign: ₹750 ÷ ₹350 | 2.14 months |
| Influencer campaign: ₹1,800 ÷ ₹350 | 5.14 months |
|---|
The averages hide something useful. Each order leaves ₹1,400 of gross profit, and it arrives on the first sale. On the normal campaign, the first order already covers the ₹750. On the influencer campaign, the first order covers ₹1,400 and the remaining ₹400 waits for the second order, about four months later. Any customer who never returns is a loss.
If Meera wins 200 customers this way in October, she spends ₹3,60,000 upfront and gets back ₹2,80,000 from first orders. The other ₹80,000 comes back only if they return.
Decide with three numbers together: CAC, first-order gross profit and how many first-time buyers actually return.
All figures are illustrative.
How long until a customer pays you back
The example's numbers are filled in. Replace them with yours.
The first order already pays back what you spent to win the customer. Repeat orders are profit towards fixed costs.
Don't confuse it with
Related terms
Want to use this at work? AI-led PPC Excellence is aFactor's 16-week program for paid ads.
Sources
- How To Calculate and Shorten Your CAC Payback Period, Shopify, 2026