Client acquisition cost (CAC) is simply what you spent to win clients, divided by how many you actually won. It only becomes useful once you compare it to what a client is actually worth to you — spending $200 to acquire a client who pays you $150 total is a losing trade no matter how it feels in the moment.
Cost to acquire each client
$0
Compare this number against the customer lifetime value calculator to see whether what you're spending to win clients actually makes sense against what they're worth over time.