Cost Per Acquisition Calculator Formula
Understand the math behind the cost per acquisition calculator. Each variable explained with a worked example.
Formulas Used
Cost Per Acquisition
cpa = acquisitions > 0 ? total_spend / acquisitions : 0Acquisitions Per $1,000 Spent
acquisitions_per_1000 = total_spend > 0 ? (acquisitions / total_spend) * 1000 : 0Variables
| Variable | Description | Default |
|---|---|---|
total_spend | Total Campaign Spend(USD) | 15000 |
acquisitions | Number of Acquisitions | 60 |
How It Works
How to Calculate Cost Per Acquisition
Formula
CPA = Total Campaign Spend / Number of Acquisitions
CPA is the bottom-of-funnel cousin of CPL. While CPL counts leads, CPA counts actual customers or completed conversions. This makes CPA the more definitive metric for measuring campaign profitability, though it takes longer to calculate because you must wait for leads to convert into customers.
Worked Example
A campaign spent $15,000 and resulted in 60 paying customers.
- 01CPA = $15,000 / 60 = $250 per acquisition
- 02Acquisitions per $1,000 = (60 / $15,000) x $1,000 = 4.0
Frequently Asked Questions
How does CPA differ from CAC?
CPA typically refers to a specific campaign or channel cost per conversion. CAC (Customer Acquisition Cost) is a broader measure that includes all sales and marketing spend divided by all new customers across all channels.
When is a high CPA acceptable?
When customer lifetime value is proportionally high. A CPA of $500 is excellent if the average customer generates $5,000 in lifetime value. Always benchmark CPA against the expected revenue from each acquired customer.
Learn More
Guide
Marketing ROI Guide
Learn how to calculate and improve marketing ROI. Covers ROAS, cost per acquisition, cost per lead, attribution models, and channel-level performance analysis.
Ready to run the numbers?
Open Cost Per Acquisition Calculator