How this calculator works
| Metric | Formula |
|---|---|
| Orders | subscribers × campaigns × delivery rate × open rate × click-to-open rate × conversion rate |
| Revenue | orders × average order value |
| ROI | (revenue − email costs) ÷ email costs |
Worked example
With these inputs:
- Currency: USD ($)
- Subscribers: 10,000
- Campaigns per month: 4
- Delivery rate: 98%
- Open rate: 35%
- Click-to-open rate: 8%
- Click-to-order conversion rate: 3%
- Average order value: 60
- Monthly email costs: 500
Monthly email revenue: $1,976. 10,000 subscribers and 4 campaigns a month bring about 33 orders and $1,976 of revenue — $3.95 for every $1 spent.
| Emails delivered | 39,200 |
|---|---|
| Opens | 13,720 |
| Clicks | 1,098 |
| Orders | 32.9 |
| ROI | 295% |
| Revenue per email sent | $0.049 |
| Revenue per subscriber per year | $2.37 |
| Click-through rate (clicks ÷ delivered) | 2.8% |
Open this example in the calculator
Campaigns vs automated flows
Campaigns are one-off sends to the list. Automated flows — welcome series, abandoned cart, post-purchase and win-back emails — are triggered by behaviour and typically earn much more revenue per email, because they arrive at the moment of intent.
If most of your email revenue comes from campaigns, setting up the core flows is usually the fastest way to improve ROI.
Why open rates are unreliable
Apple Mail Privacy Protection and some corporate filters open emails automatically, inflating open rates. Judge performance mainly on clicks, orders and revenue per email, and use click-to-open rate to compare content.
Ways to improve email marketing ROI
- Segment by interest, purchase history and engagement.
- Remove inactive subscribers to protect deliverability.
- Authenticate your domain with SPF, DKIM and DMARC.
- Test subject lines, offers and send times.
- Make every email lead to one clear action.
Open this calculator with your numbers
Every option can be set in the web address, so you can bookmark a scenario or send it to a colleague. AI assistants such as ChatGPT, Gemini, Claude and Perplexity can use the same parameters to open this calculator with your numbers and the result already on the page.
| Parameter | What it sets | Accepted values |
|---|---|---|
currency |
Currency | one of USD, INR, AED, GBP, EUR |
subscribers |
Subscribers | number from 0 to 1000000000, default 10000 |
emails |
Campaigns per month | number from 0 to 60, default 4 |
delivery |
Delivery rate | number from 0 to 100 (%), default 98 |
open_rate |
Open rate | number from 0 to 100 (%), default 35 |
ctor |
Click-to-open rate | number from 0 to 100 (%), default 8 |
conversion |
Click-to-order conversion rate | number from 0 to 100 (%), default 3 |
order_value |
Average order value | number from 0 to 10000000 (in the chosen currency), default 60 |
cost |
Monthly email costs | number from 0 to 100000000 (in the chosen currency), default 500 |
Also available as plain text for AI assistants and a free JSON API (OpenAPI spec).
Last reviewed by the Infikey Technologies team.
Disclaimer
This calculator is provided free for general information and planning only. Results are estimates based on the inputs you enter and the assumptions described on this page, reference data such as published prices may change, and actual costs and outcomes will differ. Nothing on this page is financial, legal, tax, investment or other professional advice. Infikey Technologies Private Limited, Infikey Technologies LLC and their directors, employees and affiliates make no warranty, express or implied, about the accuracy, completeness or suitability of this tool or its results, and accept no liability for any loss or damage, direct or indirect, arising from its use or from reliance on its results. Verify all figures independently and seek professional advice before making any decision. Use of this tool is at your own risk.