Email Open Rate
The percentage of email recipients who open a given email.
Definition
Email open rate is calculated by dividing the number of emails opened by the number of emails delivered, then multiplying by 100. It's a key metric for measuring email campaign effectiveness. Average open rates vary by industry but typically range from 15-25%. Subject lines, sender name, and send time significantly impact open rates.
Why It Matters
Open rate is the first gate in email marketing success—if subscribers don't open, nothing else matters. It reflects the strength of your subject lines, sender reputation, and overall list health.
While open rates have become less precise with privacy changes, they remain valuable for relative comparison. Tracking open rates over time and across segments helps identify what resonates with your audience and optimize accordingly.
Examples in Practice
A brand tests subject line emojis and sees open rates increase from 18% to 27% for promotional emails.
A B2B company segments their list by industry and personalizes subject lines, improving open rates by 35%.
A publisher notices declining open rates, cleans their list of inactive subscribers, and sees engagement metrics improve across the board.