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Customer Acquisition Cost (CAC) Calculator
Work out what it costs to win a customer — plus your LTV, LTV:CAC ratio, and payback period — in seconds. Free, private, no sign-up.
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The honest cost of winning a customer
Customer acquisition cost is simple to define and easy to calculate wrongly, usually by leaving things out.
CAC = total sales and marketing spend ÷ new customers acquired, over the same period. The word doing the work is total.
What belongs in the total
Most people include only advertising spend. That produces a CAC that looks excellent and is not real — salaries alone often double the honest figure.
- Advertising spend across all channels, not just the one you report on.
- Salaries for everyone in sales and marketing, plus agency and contractor fees.
- Software and tools — CRM, automation, analytics — and content production.
Blended CAC versus paid CAC
Both are useful. Confusing them is not — blended CAC is always the flattering number, and quoting it as though it were paid CAC is one of the more common ways a growth story falls apart under scrutiny.
- Blended CAC divides by every new customer, including the ones who arrived through word of mouth and organic search.
- Paid CAC divides by the customers that spend actually bought.
- Paid CAC is the one that tells you whether a channel can scale. Blended is the one that tells you what the business currently costs to grow.
What counts as a good CAC
There is no universal figure, because CAC only means anything against lifetime value. A high CAC is fine if customers are worth a great deal and stay for years. A low CAC is still bad if they leave in two months.
- Aim for an LTV:CAC ratio of at least 3:1.
- The payback period is the companion metric and often the more urgent one: how many months of revenue it takes to recover the cost of acquiring a customer.
- Under 12 months is generally healthy. Beyond 18, growth consumes cash faster than it generates it — solvable only if you have the cash to solve it with.
Months of revenue to recover one customer
Under 12 months is generally healthy. Beyond 18 the growth is consuming cash faster than it makes it.
The number is only useful if it is the real one
Which is the whole reason to be strict about the denominator and generous about the numerator. A flattering CAC does not make acquisition cheaper; it just delays the moment you find out.
- Use the same period for spend and customers, and allow for the lag between the two if your sales cycle is long.
- Count the customers you won, not the leads you generated.
- Include the salaries. The number is only useful if it is the real one.
Four numbers worth keeping
Why Parix.ai gives this away
We build the growth systems these numbers justify, so we have sat through the review where a flattering CAC meets a real bank balance. These tools are the same checks we run before quoting — which is why there is no paywall and no sign-up.
Work out my CACWho uses it
Growth leads comparing channels on real cost. Founders preparing for a raise. Marketing teams asked why the budget should go up.
Pair it with
The LTV:CAC Ratio Calculator for the verdict, the LTV Calculator for the other half of it, and the Marketing ROI Calculator for the campaign view.
When the fix is retention
A CAC that will not come down is often a churn problem wearing a disguise. Our product team works on the end of it that actually moves.