Email Open Rate Calculator
Calculate email delivery rate and open rate from campaign counts. Enter emails sent, delivered, and opened to get delivery rate, open rate (of delivered and of sent), unopened count, and bounces.
Input
Total messages dispatched in the campaign.
Optional. Leave blank if you don't track bounces separately (assumes all sent were delivered).
Individual recipients who opened the email (not total opens).
Output
| Metric | Value |
|---|---|
| No data yet | |
Guides
The Email Open Rate Calculator turns raw campaign counts — emails sent, delivered, and opened — into the delivery and open-rate percentages marketers actually report on, plus the raw unopened and bounced counts behind them.
The formulas
Delivery Rate % = Emails Delivered ÷ Emails Sent × 100
Open Rate (of Deliv.) = Unique Opens ÷ Emails Delivered × 100
Open Rate (of Sent) = Unique Opens ÷ Emails Sent × 100Most email platforms report open rate as a percentage of delivered mail — that's the "Open Rate (of Delivered)" row. This calculator also shows open rate as a percentage of everything sent, a stricter view that factors bounces back in, so a high open rate can't hide a bad delivery rate.
How to use it
- Enter Emails Sent — the total number of messages your campaign dispatched.
- Enter Emails Delivered — how many actually arrived (excludes hard/soft bounces). Leave this blank if you don't track bounces separately; the calculator then assumes every sent email was delivered.
- Enter Unique Opens — the number of individual recipients who opened the email, not total opens (someone opening twice only counts once).
The results update instantly and show delivery rate, both open-rate views, how many delivered emails went unopened, and how many bounced.
What's a good open rate?
Typical open rates run roughly 15–25% across industries, though it varies a lot by list quality, subject line, and sender reputation. Delivery rate is worth watching separately — a rate consistently under ~95% usually points to list hygiene problems (stale addresses, spam-trap hits) rather than anything about the email's content.
Privacy
All calculations run entirely in your browser. Your campaign numbers are never uploaded or stored.
Use it from code
From 3 credits per callREST API
curl -X POST https://api.iotools.cloud/v1/tool/email-open-rate-calculator \
-H "Authorization: Bearer YOUR_API_KEY" \
-H "Content-Type: application/json" \
-d '{
"emailsSent": "10000",
"emailsDelivered": "9600",
"uniqueOpens": "2400"
}'Swap in your own key from your account. The tool's fields are the body — no wrapper.
Ask an AI agent
Use the IOTools `email-open-rate-calculator` tool (Email Open Rate Calculator) on this input:
YOUR_INPUT_HEREPaste this at any agent connected to the IOTools MCP server, then add your input.