Click-to-Open Rate
The percentage of email openers who clicked a link.
1 min readLast updated Apr 2026
Formula
(Unique Clicks/Unique Opens) × 100
Example: 800 ÷ 8,000 × 100 = 10% CTOR
The percentage of email openers who clicked a link.
Why It Matters
CTOR isolates email content effectiveness from subject line performance. If your open rate is high but CTOR is low, your subject line worked but the email content didn't deliver. This metric helps you diagnose where to focus optimization—subject lines or email body.
Formula
(Unique Clicks/Unique Opens) × 100
Example: 800 ÷ 8,000 × 100 = 10% CTOR
Practical Example
Scenario
A pet supplies brand sees 8,000 opens and 800 clicks on a new product launch email.
Calculation
800 ÷ 8,000 × 100 = 10% CTORResult
With a 10% CTOR (above the 8-10% benchmark), the email content is resonating well. They replicate the email structure—hero product image, benefit-focused copy, single CTA—in future launches.
Pro Tips
- 1Aim for 10-15% CTOR for campaigns, 15-25% for flows
- 2If CTOR is low but open rate is high, your subject line overpromised—align content with subject
- 3Test image-to-text ratio—some audiences prefer image-heavy, others prefer text-focused emails
- 4Personalize email content (not just subject lines) to boost CTOR
Common Mistakes to Avoid
Only optimizing subject lines while ignoring email body content when CTOR is the real issue
Comparing CTOR across vastly different email types (promotional vs transactional)
Ignoring mobile preview—if content doesn't hook above the fold, CTOR suffers