HesapHanem

Cost Per Acquisition Calculator

Enter your marketing spend and customers acquired to find your CPA.

How it is calculated

The tool divides the money spent by the customers won: CPA = total spend ÷ customers acquired. Spend is in US dollars and customers is a count, so the answer is dollars per customer, rounded to cents. Customers must be at least 1 and spend cannot be negative; anything else, including zero customers where the division is undefined, gives no result. A spend of 0 is allowed and returns a CPA of $0.00. Use the same period and the same campaign scope for both numbers: if the spend covers March, count only the customers acquired from that spend in March. The tool also echoes the spend and the customer count. It does not look at revenue, repeat purchases or customer lifetime value, so it says nothing about profit by itself.

Worked example

A campaign cost $7,350 in total and brought in 63 new paying customers. CPA = 7,350 ÷ 63 = 116.666..., which the tool shows as $116.67 per customer, together with the spend $7,350.00 and 63 customers. If each customer is worth more than $116.67 in margin over their lifetime, the campaign pays for itself; if each is worth less, it loses money.

Try this example →

Common mistakes

  • Counting leads, clicks or sign-ups as customers. CPA here is per acquired customer; if you divide by leads you get a cost per lead, which is much lower.
  • Leaving costs out of the spend, such as agency fees, creative production or tool subscriptions. A CPA built only on ad platform spend looks better than the real figure.
  • Mixing periods, for example this month's spend with customers who converted last month from earlier ads. Match the spend to the customers it actually produced.
  • Entering 0 customers because the campaign has not converted yet. The tool gives no result rather than an infinite CPA; wait for at least one conversion, and note that fractions below 1 are rejected as well.
  • Judging CPA without the order value. A $116.67 CPA is fine for a product earning $500 margin and ruinous for one earning $40.

Sources

About this calculator

Cost per acquisition (CPA) measures how much a business spends, on average, to win one paying customer or conversion — calculated simply as total marketing spend ÷ number of customers acquired. It's one of the most-watched metrics in performance marketing because it directly ties ad spend to revenue-generating outcomes rather than vanity metrics like clicks or impressions.

This calculator divides your spend by the customers you acquired over the same period to give a clean CPA figure. Marketers and growth teams use it to compare channels (search ads versus social versus affiliate), decide which campaigns to scale, and check that CPA stays comfortably below customer lifetime value so the business remains profitable.

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Comments (1)

  • Editorial team

    CPA only says what a customer cost, not whether that was worth paying. Set it against the gross profit one customer brings over their time with you, and keep spend and customers on the same dates and the same channel. Counting ad spend but leaving out agency or tool fees flatters the number. Which costs do you put under spend?

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