Email Cost Per Acquisition Calculator
Calculate your CPA, campaign ROI, and revenue per conversion. Compare the efficiency of every campaign you send.
Enter Your Campaign Data
Total cost to send the campaign
Sales, sign-ups, or goal completions
Enter to calculate ROI and profit
Your Results
Cost Per Acquisition
—
Campaign Cost ÷ Conversions
Revenue Per Conversion
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Revenue ÷ Conversions
Email CPA Benchmarks
Email CPA varies widely by industry and conversion goal. Email consistently outperforms other channels on CPA due to low send costs.
E-commerce
£1–£15
Product purchase
B2B SaaS
£20–£100
Trial or demo sign-up
Lead Gen
£5–£40
Form completion
How Email CPA is Calculated
Cost Per Acquisition (CPA) = Campaign Cost ÷ Conversions
ROI = ((Revenue − Campaign Cost) ÷ Campaign Cost) × 100
ROAS = Revenue ÷ Campaign Cost
Campaign cost includes ESP fees, copywriting, design, and any tool costs attributed to the send. Conversions should only include actions directly attributable to the campaign (use UTM tracking).
Email CPA: Measuring the True Efficiency of Your Email Campaigns
Cost per acquisition (CPA) measures how much you spend on email marketing for each customer, sale, or goal completion you generate. It's one of the most direct ways to evaluate campaign efficiency and compare email performance against other marketing channels. Unlike vanity metrics such as open rate, CPA ties directly to business outcomes and budget justification.
Email marketing consistently delivers among the lowest CPAs of any digital channel. Because email infrastructure costs are relatively low compared to paid advertising, even modest conversion rates produce strong CPA figures. An email campaign costing £500 that generates 50 sales has a CPA of £10 — a figure that would be difficult to match with paid social or search for most industries.
What to Include in Campaign Cost
When calculating email CPA, include all costs attributable to producing and sending the campaign: ESP fees (calculated on a per-send or monthly basis proportional to campaigns sent), copywriting costs, design time, landing page costs, and any tool fees used specifically for that campaign. For in-house teams, you can include a proportion of staff time if you want a fully loaded CPA. Many teams track direct spend only, which produces a lower CPA but one that's easier to measure consistently.
How to Reduce Email CPA Over Time
Reducing email CPA comes from two levers: reducing cost or increasing conversions. On the cost side, better list hygiene means you're paying to send to fewer unengaged contacts. Reusing templates, automating campaigns, and improving workflow efficiency all reduce the variable cost per send. On the conversion side, better segmentation, personalisation, and send-time optimisation improve conversion rates without increasing list size or spend. The highest-leverage improvement is usually a better landing page — email can drive clicks efficiently, but if the landing page doesn't convert, CPA suffers regardless of campaign quality.