How to Calculate Customer Acquisition Cost
Customer acquisition cost is what you spent to win a customer. The formula is simple. The arguments are about what goes in the numerator and what counts as a customer.
The basic formula
Customer acquisition cost equals the costs you agreed to include, divided by the number of new customers those costs produced in the same period.
If paid media is the question, a useful version is ad spend divided by new customers from that spend. If you want a fuller number, add the agency or in-house cost, creative production, and tools. Write the formula down so next month uses the same one.
Do not mix the denominator
Leads are not customers. Trials are not customers. A form fill from outside your service area is not a customer. If the denominator is loose, the cost looks better than the business is.
Pick one definition. New paying customers is the cleanest. If the sales cycle is long, report cost per qualified opportunity beside it, and do not rename that number CAC.
Read it against value
A CAC of a few hundred dollars is fine for one business and fatal for another. Compare it with gross profit per customer, or with the revenue you keep after delivery. Payback period matters when the first purchase is small and the relationship is long.
Channel CAC should be reported separately. Blended CAC can hide a search program that works and a social program that does not, or the reverse. Our performance marketing work treats that split as normal, not optional.