Email Open Rate Calculator Formula
Understand the math behind the email open rate calculator. Each variable explained with a worked example.
Formulas Used
Open Rate
open_rate = emails_delivered > 0 ? (emails_opened / emails_delivered) * 100 : 0Emails Not Opened
unopened = emails_delivered - emails_openedVariables
| Variable | Description | Default |
|---|---|---|
emails_opened | Emails Opened | 800 |
emails_delivered | Emails Delivered | 4000 |
How It Works
How to Calculate Email Open Rate
Formula
Open Rate = (Emails Opened / Emails Delivered) x 100
Open rate indicates how well your subject lines and sender reputation attract attention in crowded inboxes. Use delivered emails (not sent emails) as the denominator to exclude bounces, which the recipient never had a chance to see. Note that privacy features like Apple Mail Privacy Protection can inflate open rates by pre-loading tracking pixels.
Worked Example
An email campaign delivered 4,000 emails and 800 were opened.
- 01Open Rate = (800 / 4,000) x 100 = 20%
- 02Unopened = 4,000 - 800 = 3,200
Frequently Asked Questions
What is a good email open rate?
Average open rates range from 15-25% across industries. B2B emails tend toward 20-25%. Promotional B2C emails average 15-20%. Transactional emails (order confirmations, receipts) often exceed 60%.
How can I improve open rates?
Personalize subject lines, test send times, clean your list of inactive subscribers, avoid spam trigger words, build sender reputation through consistent sending, and segment your audience for relevance.
Ready to run the numbers?
Open Email Open Rate Calculator