Cost Per Acquisition (CAC), sometimes called Customer Acquisition Cost, answers a simple question: how much did it cost you to get one new paying client? You add up everything you spent on marketing in a period, then divide by how many new customers you actually won. CAC turns abstract spending into a clear price tag you can compare against what a client is worth.
How do you calculate CAC?
CAC is total marketing spend in a period divided by the number of new customers acquired in that same period. "Marketing spend" means every dollar that went toward getting clients: ad budget, funnel software, and any contractor or agency fees tied to acquisition.
Here is a plain example, using illustrative numbers:
| Item | Amount |
|---|---|
| Ad spend (one month) | $2,000 |
| Funnel and email tools | $200 |
| New paying clients won | 10 |
| CAC | $220 per client |
So each new client cost $220 to acquire. On its own that number means little. It becomes useful only when you compare it to what a client is worth over time.
How does CAC differ from related terms?
CAC is what a client costs to win; customer lifetime value (CLV) is what that client is worth across the whole relationship. The two are a pair. A widely used benchmark is a CLV-to-CAC ratio of about 3:1 — a client should be worth at least three times what they cost to acquire (Klipfolio).
A few neighbours people mix up:
- Cost per lead (CPL): what you pay for a contact who is interested but has not bought yet. Many leads become one customer, so CPL is lower than CAC.
- Cost per click (CPC): what you pay each time someone clicks an ad. Several clicks make one lead, and several leads make one customer.
- CLV: the total value from a client over the relationship, including renewals, upsells, and repeat programs.
Think of it as a ladder: clicks lead to leads, leads lead to customers. CAC sits at the top of that ladder.
When and why should coaches use CAC?
Track CAC the moment you start spending money to attract clients rather than relying on referrals alone. It is the single check that tells you whether paid traffic is building your practice or quietly draining it. Using the illustrative numbers above, a $220 CAC against a client worth roughly $900 over a year of sessions is about a 4:1 ratio — a signal you have room to invest more in acquisition. If a client were worth only $250, you would barely cover costs and the model would not scale.
CAC also guides where to invest. Knowing it lets you work on raising the value of each client — through stronger offers, renewals, and add-ons — so the same acquisition cost stretches further.
What is the most common CAC mistake?
The most common error is counting only ad spend and ignoring the rest. If you spend $2,000 on ads but another $800 on the software and help that made those ads convert, your real CAC is $280 per client, not $220. Leaving out those costs makes acquisition look more profitable than it is — the gap that turns a "winning" campaign into a slow loss. Always include every dollar tied to winning the client, then weigh it against lifetime value, never against a single sale.