💰 Customer Acquisition Cost (CAC) Calculator
A customer acquisition cost calculator from marketing and sales spend, with an optional LTV:CAC ratio to check if growth spend is actually healthy.
What Customer Acquisition Cost (CAC) Calculator Does
Customer Acquisition Cost is deceptively simple to compute and easy to compute wrong in practice, because the real difficulty is deciding what belongs in the numerator. Ad spend is the obvious part; sales salaries, commissions, agency fees, and the tools used to run campaigns are less obvious but still real costs of acquiring a customer — leaving them out makes CAC look artificially healthy.
CAC on its own is not a verdict — it only becomes meaningful once compared against what a customer is actually worth, which is what the LTV:CAC ratio is for. A high CAC can still be a good business if lifetime value is high enough; a low CAC is not automatically healthy if customers churn before ever covering the cost of acquiring them.
How to Use Customer Acquisition Cost (CAC) Calculator
- Enter total marketing spend and total sales spend for a period
- Enter the number of new customers acquired in that same period
- Optionally enter customer lifetime value to see your LTV:CAC ratio
Formula Used by Customer Acquisition Cost (CAC) Calculator
Customer Acquisition Cost
CAC = (Total marketing spend + Total sales spend) ÷ New customers acquired
Worked example
$10,000 marketing spend, $5,000 sales spend, 500 new customers
- (10,000 + 5,000) ÷ 500
Result: $30 CAC per customer
How to Read Your Result
The 3:1 LTV:CAC benchmark is a rule of thumb, not a law
It is widely cited as a healthy target because it typically leaves enough margin to cover overhead beyond acquisition and still be profitable — but the right ratio for a specific business depends on gross margin, how long it takes to recover CAC (payback period), and how capital-constrained the business is.
A rising CAC over time is a common early warning sign
As the cheapest, most efficient acquisition channels get saturated, CAC often climbs as a business pushes into more expensive channels or broader targeting to keep growing — tracking CAC over time (not just as a single snapshot) surfaces this trend before it becomes a crisis.
Limitations & Accuracy Notes
- Uses total marketing and sales spend, which can slightly overstate true acquisition cost if some of that spend also serves retention or upsells to existing customers.
- Does not account for the payback period — how many months of revenue it takes to recover the CAC — which matters as much as the raw ratio for cash-constrained businesses.
- LTV itself is an estimate with its own assumptions and error margin; a CAC:LTV ratio is only as reliable as the LTV figure feeding it.