Email Marketing ROI Calculator
Calculate email marketing ROI from list size, open rate, conversion rate, and platform cost.
Returns revenue per subscriber and overall campaign ROI.
The full revenue chain
Monthly revenue = list size × open rate × CTR × conversion rate × AOV × sends/month
Each link in that chain is a percentage. A list of 5,000 with a 25% open rate, 3% click-through, 2% conversion, $80 AOV, sending 4 times a month works out to: 5,000 × 0.25 × 0.03 × 0.02 × $80 × 4 = $240/month. Small percentage changes compound: doubling the conversion rate alone doubles the revenue.
Benchmarks (Mailchimp and HubSpot 2024 industry data)
| Metric | Average | Good | Excellent |
|---|---|---|---|
| Open rate | 21.3% | 30%+ | 40%+ |
| Click-through rate | 2.6% | 5%+ | 10%+ |
| Conversion rate | 1 to 3% | 4 to 6% | 8%+ |
| Unsubscribe rate | 0.1 to 0.2% | under 0.1% | under 0.05% |
| Bounce rate | under 2% | under 1% | under 0.5% |
Open rates have become unreliable since Apple Mail Privacy Protection launched in 2021 — Apple silently pre-fetches images for all subscribers, registering an “open” whether they actually read the email or not. Most lists now show inflated open rates (35 to 50% reported when real engagement is 20 to 25%). CTR and conversion rate are the trustworthy numbers.
Revenue per email subscriber (RPE)
The DMA’s long-standing rule of thumb: a healthy list generates about $1 per subscriber per month. A 5,000-person list “should” produce around $5,000/month if monetised well. The top quartile of e-commerce lists run $2 to $5 per subscriber per month; the bottom half do far less, often under $0.30. List quality (engagement, segmentation, recency) matters more than raw size.
Where senders leave money
- Sending too rarely. Once a month is not enough to stay top-of-mind. Twice a week is closer to optimal for most retail, with one well-written newsletter plus one promotional/transactional.
- Sending too often. Daily for non-content lists causes fatigue and unsubscribes. Watch unsubscribe rate per send — if it climbs over 0.3%, cut frequency.
- No segmentation. Sending the same email to a brand-new subscriber and a five-year customer is wasted reach. Segmented campaigns generate 760% more revenue (Campaign Monitor study, 2019).
- Weak subject lines. Open rate is decided in 30 to 50 characters of preview text. A/B test every send — even a 5% lift compounds.
- Forgetting mobile. Over 60% of email opens happen on mobile. If your email looks bad on a phone, the click never happens.
ROI calculation
ROI % = (revenue − platform cost) ÷ platform cost × 100
A $5,000 monthly revenue against a $100 Mailchimp plan is a 4,900% ROI. Email genuinely is the highest-ROI marketing channel — DMA studies have measured average returns of $36 to $42 per $1 spent, far ahead of paid social or display.