CAC Calculator
Customer acquisition cost, LTV:CAC ratio, and payback period — calculated as you type, with the benchmarks that say whether the numbers are healthy. Free, no signup, and nothing leaves your browser.
Your numbers
Use one month (or average the last three) for spend and customers.
Optional — add these three to get LTV, LTV:CAC, and payback.
Customer acquisition cost
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Enter spend and new customers to calculate.
LTV
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LTV : CAC
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CAC payback
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Numbers update as you type and never leave your browser — nothing is stored or sent.
How this calculator works
CAC = (marketing spend + sales spend) ÷ new customers, over the same month. LTV uses the standard subscription shorthand: monthly gross profit per customer ÷ monthly churn rate. Payback is CAC ÷ monthly gross profit per customer — how many months until a customer covers their own acquisition cost.
The health markers use the common SaaS heuristics: an LTV:CAC ratio of 3× or better and payback under 12 months. They're rules of thumb, not laws — a bootstrapped company may want faster payback; a well-funded one may tolerate slower.
If the inputs are hard to assemble, that's a finding in itself: CAC is only as good as your spend and conversion tracking. A recurring report that joins ad spend with real revenue data is the fix — it's one of the first things teams delegate to an AI marketing agent. And if CAC comes out high, start with an ad account audit — wasted spend is the fastest CAC lever there is.
CAC questions, answered
What is CAC?
Customer acquisition cost (CAC) is what you spend, on average, to win one new customer. It is calculated by dividing total acquisition spend — marketing, and usually sales — by the number of new customers acquired in the same period.
What is the CAC formula?
CAC = (marketing spend + sales spend) ÷ new customers acquired, all measured over the same period. Using marketing spend alone gives marketing-only CAC; including sales costs gives blended CAC, which is the number investors usually mean.
What is a good CAC?
There is no universal good CAC — it depends entirely on what a customer is worth to you. The useful benchmarks are ratios: an LTV:CAC ratio of 3 or higher and a CAC payback period under about 12 months are the standard health markers for SaaS and subscription businesses.
What is the difference between CAC and CPA?
CPA (cost per acquisition/action) usually measures the cost of a single conversion event in an ad platform — a lead, a signup, a trial. CAC measures the full cost of acquiring a paying customer across all channels. A $40 CPA on trials with a 25% trial-to-paid rate implies a $160+ CAC before you count any other spend.
Should CAC include salaries and tools?
For blended CAC, yes: include the people and tooling whose job is acquisition — marketing salaries, agency and contractor fees, and software. Ad-spend-only CAC is a useful channel-efficiency number, but it flatters the true cost of growth, sometimes dramatically.
How do I lower my CAC?
The levers, in rough order of speed: cut wasted ad spend (an account audit usually finds some), improve conversion rates so the same spend yields more customers, shift mix toward channels that compound like SEO and referrals, and improve targeting so you attract better-fit buyers who close faster.