KKPI Formulas
Marketing KPI Formula

CPA Formula

CPA, or cost per acquisition, measures cost per conversion or acquired customer depending on campaign definition.

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Simple formula

Campaign Cost / Number of Acquisitions

The formula uses these inputs:

  • Campaign Cost: enter your value in the calculator or spreadsheet.
  • Acquisitions: enter your value in the calculator or spreadsheet.

Excel formula

Use this Excel formula as a starting point. Replace the sample cell references with the cells in your worksheet.

=IFERROR(B2/C2,0)

Google Sheets formula

In most cases, the Google Sheets version uses the same structure as Excel.

=IFERROR(B2/C2,0)

Power BI DAX measure

Use this DAX pattern as a starting point and rename measures or columns to match your Power BI model.

CPA =
DIVIDE(
    [Campaign Cost],
    [Acquisitions]
)

SQL example

This generic SQL pattern can be adapted to your warehouse table names and column names.

SELECT
    /* replace with your formula */ AS cpa
FROM kpi_data;

CPA calculator

Result—

How to interpret CPA

Use this KPI with trend data, targets, and related metrics. A single value is less useful than a consistent definition tracked over time.

Important: KPI definitions can vary by company, accounting policy, analytics platform, or reporting standard. Keep the definition consistent when comparing periods.

Common mistakes

  • Mixing different time periods in the numerator and denominator.
  • Using totals that do not match the KPI definition used by your company.
  • Comparing results across teams or industries without context.

Related KPI formulas

Frequently asked questions

What is the CPA formula?

The common CPA formula is: Campaign Cost / Number of Acquisitions.

How do you calculate CPA in Excel?

Use this Excel formula pattern: =IFERROR(B2/C2,0). Replace the cell references with your own data.

Can this KPI be calculated in Power BI?

Yes. Use the DAX measure on this page as a starting point and adjust table and column names to match your model.