The Formula
Email marketing ROI compares what email earns you with what it costs:
ROI (%) = (Revenue from email − Cost of email) ÷ Cost of email × 100
If your emails generated $3,000 in sales over a quarter and cost you $600 to run, your ROI is ($3,000 − $600) ÷ $600 × 100 = 400%. In plain terms, every dollar you spent came back with four dollars of profit on top.
The formula is simple. The work is in counting revenue and costs honestly, which the rest of this guide covers.
Step 1: Choose a Time Period
Pick a period long enough to smooth out one-off results, such as a quarter or a year. Monthly ROI swings too much for most small businesses, especially if you run occasional launches.
Use the same period for both revenue and costs, and keep it consistent when you compare results over time.
Step 2: Add Up Your Costs
Include every cost that exists because you do email marketing:
- Platform fees. Your email tool's subscription for the period.
- Transaction fees. Any fees on sales processed through your email platform, such as AWeber's 1.0% on Lite or 0.6% on Plus.
- Paid help. Freelance writers, designers or agencies.
- Your time. Hours spent writing, designing and managing, multiplied by a reasonable hourly value.
- Tools. Any extra software used only for email, such as design subscriptions.
Many people leave out time, which makes ROI look better than it is. Include it, even as an estimate.
Step 3: Count Revenue From Email
This is the harder part. The cleanest measure is direct revenue: purchases made by people who clicked an email and bought within a set window, such as seven days.
Your email platform or store can often track this. On AWeber Plus, sales tracking shows which emails led to purchases made through its commerce tools. Store platforms and analytics tools can attribute sales from email links with tracking parameters.
Some businesses also count assisted revenue, where email played a part but wasn't the last click. If you include it, label it clearly and use a consistent rule so you don't overstate results.
A Worked Example
Here's a hypothetical example for a small online course business over one quarter. The figures are illustrative assumptions, not benchmarks.
| Item | Amount |
|---|---|
| Email platform (AWeber Plus, 2,500 subscribers, monthly billing) | $165 ($55 × 3) |
| Transaction fees on course sales (0.6% of $4,200) | $25.20 |
| Owner's time: 4 hours a week × 13 weeks × $30 an hour | $1,560 |
| Total cost | $1,750.20 |
| Course sales from email clicks | $4,200 |
| ROI | ($4,200 − $1,750.20) ÷ $1,750.20 × 100 = 140% |
Without counting time, the ROI would look like more than 2,000%. Including time gives a truer picture, and shows that saving writing time, such as with templates or AI drafting tools, directly improves return.
Other Useful Numbers
ROI is one view. These complementary measures help you understand what's driving it:
Email revenue for the period divided by average list size. Tells you what each subscriber is worth.
Revenue divided by total sends. Useful for comparing campaigns of different sizes.
Purchases divided by clicks. Shows how well your offer and landing page perform.
Platform cost divided by list size. Rises if you keep inactive subscribers.
See email marketing metrics for how these fit together.
How to Improve Your Email ROI
You can raise ROI by increasing revenue, reducing cost or both:
- Automate your best-performing emails so they work for every new subscriber. See email automation workflows.
- Segment your list so offers reach the people most likely to want them. See email segmentation.
- Clean inactive subscribers to lower platform costs and improve deliverability. See email list hygiene.
- Test subject lines and calls to action to lift clicks. See A/B testing emails.
- Cut writing time with templates and AI drafting tools, then edit for your voice.
- Choose annual billing once your plan is settled.
Common ROI Mistakes
- Ignoring time costs, which makes email look far more profitable than it is.
- Counting every sale from a subscriber, even ones unrelated to email.
- Comparing with industry averages instead of your own past performance.
- Measuring too short a period, so one launch skews the result.
AWeber Plus includes sales tracking for purchases made through its commerce tools, plus unlimited automations. Start free.
Email Marketing ROI FAQs
How do you calculate email marketing ROI?
Subtract the cost of email from the revenue it generated, divide by the cost and multiply by 100.
What costs should I include in email ROI?
Platform fees, transaction fees, paid help, tools and the value of your own time.
What is a good email marketing ROI?
Any positive ROI means email pays for itself. Compare against your own previous periods rather than averages.
How do I track revenue from email?
Use your email platform's sales tracking or tracked links in your store or analytics tool.