Email Open Rate Calculator
Calculate your email open rate instantly. Industry benchmark is 21.5%. Free, browser-based, no sign-up.
How Email Open Rate Calculator Works
Open Rate = (Unique Opens ÷ Emails Delivered) × 100. Use delivered count, not sent count — bounced emails don't count toward the denominator. Important: Apple Mail Privacy Protection has inflated open rates since 2021 by auto-opening emails, so treat absolute percentages with caution. Focus on trends month-over-month instead. Mailchimp's 2024 benchmark is 21.5% average across industries.
Email Open Rate Benchmarks by Industry
| Label | Meaning |
|---|---|
| Above 30% | Excellent — highly engaged list or strong subject lines |
| 21–30% | Above average — Mailchimp industry benchmark range |
| 15–21% | Average — review subject lines and send timing |
| Below 15% | Below average — audit list hygiene and segmentation |
Frequently Asked Questions
What is email open rate?
Email open rate measures the percentage of delivered emails that recipients open. Formula: (Unique Opens ÷ Emails Delivered) × 100. It's the primary indicator of subject line effectiveness and sender reputation. Note: Apple Mail Privacy Protection has inflated open rates since 2021 — treat absolute numbers with caution and focus on trends.
What is a good email open rate?
Mailchimp's 2024 benchmark is 21.5% average across all industries. Government (28.77%) and non-profit (25.17%) perform highest. Retail and ecommerce typically run 15–20%. Compare against your own historical trend, not just the industry average.
Why did my open rate suddenly drop?
Common causes: deliverability issue (check spam folder placement), send time change, subject line quality drop, list fatigue (sending too frequently), or a segment with disengaged subscribers. Check bounce and spam complaint rates alongside open rate.
Is my data stored?
No. Browser-only.
Can I use this on mobile?
Yes.
About This Tool
Built by the Calcyo team and last updated June 2026. All calculations follow industry-standard methodology. No data leaves your browser — calculations run entirely client-side using JavaScript. If you spot an error in the formula or benchmark data, email us at support@calcyo.xyz.