Marketing and online sales

Cost per acquisition calculator

Define the acquisition event consistently before comparing campaigns.

Your numbers

Use the units shown. Results update as you change valid inputs.

YOUR RESULT

Define the acquisition event consistently before comparing campaigns.

THE NUMBERS, EXPLAINED

How to use this calculator.

Define the acquisition event consistently before comparing campaigns.

Start with your inputs

Enter spend (£), acquisitions. Keep amounts in the units shown on each field. The example is a starting point, not a recommended value.

InputExample value
Spend (£)1000
Acquisitions50

A worked example

With the example inputs above, cpa (£) is 20. Change the inputs to explore your own scenario.

Putting the example numbers into the formula

CPA (£)
(1000) ÷ (50) = 20

All results for the example inputs above
ResultExample answer
CPA (£)20

How this is calculated

CPA (£)

a ÷ b

Symbols and units
a
Spend (£)
b
Acquisitions

Use the units shown. A list keeps the order in which you enter its values. The symbol ^ means “raised to the power of”.

Assumptions and limits

Define the acquisition event consistently before comparing campaigns.

Calculations use the values you enter. Blank or invalid inputs show an error instead of silently substituting zero. Results are displayed to useful precision; calculations retain the underlying numeric precision.

Questions about this tool

What does the result tell me?

CPA (£). The result applies to the method and inputs described above. Check the units and assumptions before using it in a decision.

Why might another calculator differ?

Differences in units, rounding, timing or model definitions can produce different answers. Compare the input definitions and the method, rather than only the final number. For this tool: Define the acquisition event consistently before comparing campaigns.

Are my inputs stored or sent to AI?

Calculations on this page happen in your browser. The separate AI question finder sends its submitted conversation to OpenAI; these calculator fields are not sent. Favourites and recent tool names are stored locally. A shared link contains the inputs you choose to include.

Review status

Software example and browser checks are recorded in our quality report. No external expert review is claimed. Created with coding assistance; calculations run as ordinary browser code.

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