Open Rate is the percentage of email recipients who opened an email campaign. It’s one of the most fundamental metrics in email marketing, indicating how effective your subject lines and sender reputation are at capturing attention.
Calculating Open Rate
Open Rate = (Unique Opens / Emails Delivered) × 100
For example, if you sent 10,000 emails, 9,500 were delivered, and 2,375 were opened, your open rate would be 25%.
Industry Benchmarks
Average open rates vary by industry:
- B2B: 15-25%
- E-commerce: 15-20%
- Non-profit: 20-25%
- Media/Publishing: 20-25%
Factors Affecting Open Rate
Subject Line
The most critical factor. Compelling, relevant, and curiosity-inducing subject lines drive higher opens. Personalization and urgency can also boost performance.
Sender Name
Recipients are more likely to open emails from recognizable, trusted senders. Use a consistent, human-friendly sender name.
Send Time
Timing matters. Test different days and times to find when your audience is most likely to engage.
Preview Text
The preview text (preheader) appears after the subject line in most email clients. Use it to complement your subject line and provide additional context.
Limitations of Open Rate
With Apple’s Mail Privacy Protection (MPP) and other privacy features, open tracking has become less reliable. Many opens are now pre-loaded by privacy features, inflating reported open rates. Consider using click-through rate as a more reliable engagement metric.
While open rate remains a useful directional metric, modern email marketers should use it alongside other engagement metrics for a complete picture of campaign performance.