Email Marketing ROI: How to Measure the Return on Your Emails
How to calculate email marketing return on investment realistically — the formula, what to count, and how to improve it over time without inventing numbers.
Return on investment tells you whether email is worth the time and money you're putting in. This guide explains how to calculate it simply and honestly — no inflated industry averages, just your own numbers.
The basic formula
ROI = (Return - Cost) ÷ Cost. The 'Return' is the revenue or value your emails produced; the 'Cost' is everything you spent, including your time. A positive result means email paid for itself and more; a negative one means it didn't.
Estimate your real costs
Costs to include
- Your platform subscription (what you actually pay per month)
- The hours you or staff spend writing, designing and sending
- Any extra spend on tools, images or agencies
- For higher-volume senders, any overage or transactional costs
Estimate your return
The cleanest return is the revenue you can point to your emails creating: attributed sales from tracked links, revenue from automated sequences, and repeat purchases driven by email. For B2B, convert to a value for meetings and qualified leads if you track them.
Tip
Use your platform's built-in attribution and ecommerce tracking if you have it. Even a rough, conservative estimate beats repeating someone else's headline number.
A worked, honest example
Say you pay £40 a month for your platform and spend about 3 hours a month on email, which you value at £30 an hour — about £130 total. If the email drives £400 of attributed sales, your ROI is roughly (400 - 130) ÷ 130, about 2.1, or 210%. The exact numbers are yours to fill in.
| Line | Example |
|---|---|
| Platform cost | £40 / month |
| Time cost | £90 / month |
| Total cost | £130 / month |
| Attributed revenue | £400 / month |
| ROI | ≈ 210% |
Improving ROI over time
Ways to move the number
- Send to smaller, more relevant segments to lift conversion.
- Automate your best sequences (welcome, cart, win-back).
- Improve your subject lines and calls to action.
- Reduce time spent with templates and a repeatable process.
- Watch unsubscribe and complaint rates to protect deliverability.
When email isn't showing ROI
If cost exceeds return month after month, look first at whether people are actually receiving your email (deliverability), then at relevance (segmentation), then at your offer. A tiny, engaged, well-targeted list usually beats a huge irrelevant one.
Important
Any percentage you see quoted online — including any seen here — is an average, not a guarantee. Calculate your own figures honestly for your own business.
Compare platforms and find one priced for your list size.
Frequently asked questions
What is a good email marketing ROI?
There's no reliable universal figure. The honest answer is: a positive return that grows over time, based on your own measured numbers.
Should I count my time as a cost?
Yes, if you value your time. Include it so your ROI tells you whether email is truly worth the effort.
How do I track revenue from email?
Use link tracking and your platform's ecommerce measurement, or tag links so your analytics tool attributes conversions to email traffic.