Open Rate
Quick Definition
Open Rate is a metric that measures the percentage of recipients who open an email compared to the total number of emails delivered, indicating the effectiveness of email subject lines and overall engagement.
Interactive Tools
Open Rate is calculated by dividing the number of emails opened by the number of emails delivered and then multiplying by 100. This metric helps evaluate how well your subject lines and preheader text are performing in enticing recipients to open your emails.
How Open Rate is Calculated
Formula: (Emails Opened ÷ Emails Delivered) × 100
For example, if you send 1,000 emails and 250 recipients open them, your open rate would be 25%.
Industry Benchmarks
Average open rates vary by industry:
- Retail: 18-22%
- Healthcare: 22-28%
- Education: 20-28%
- Technology: 16-24%
- Non-profit: 24-31%
Factors Affecting Open Rate
Subject Line Quality
- Keep it under 50 characters
- Create urgency or curiosity
- Personalize when possible
- Avoid spam trigger words
Sender Reputation
- Consistent sending patterns
- Low spam complaint rates
- Proper authentication (SPF, DKIM, DMARC)
- Clean email list
Send Time Optimization
- Test different days and times
- Consider your audience’s timezone
- Avoid major holidays unless relevant
Limitations of Open Rate
Privacy Changes: iOS 15+ and other email clients now preload images, which can inflate open rates since opens are typically tracked through pixel loading.
Not Always Accurate: Opens are tracked when images load, so text-only email clients or users with images disabled won’t register opens.
Best Practices for Improving Open Rate
- A/B Test Subject Lines - Test different approaches to see what resonates
- Segment Your List - Send more targeted content to specific groups
- Clean Your List Regularly - Remove inactive subscribers
- Optimize Preview Text - Use preheader text effectively
- Build Trust - Use a recognizable sender name and address
Using Open Rate with Other Metrics
Open rate should be analyzed alongside:
- Click-through rate - Measures engagement beyond opening
- Conversion rate - Shows actual business impact
- List growth rate - Indicates list health
- Unsubscribe rate - Reveals content quality issues
A high open rate with low click-through rate might indicate compelling subject lines but poor email content. Conversely, a moderate open rate with high click-through rate suggests highly engaged subscribers.
Remember: Open rate is just one piece of the puzzle. Focus on overall engagement and conversions to measure true email marketing success.
Related Terms
Bounce Rate
Bounce Rate in email marketing refers to the percentage of emails that could not be delivered to recipients' inboxes and were returned to the sender.
Click-Through Rate
Click-Through Rate (CTR) is the percentage of email recipients who clicked on one or more links contained in an email, measuring engagement and content effectiveness.
Engagement Rate
Engagement Rate is a metric that measures the level of interaction and interest that recipients show towards an email, typically calculated by dividing the number of interactions (clicks, replies, etc.) by the total number of delivered emails.
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