What Is Click-to-Open Rate (CTOR)?
Click-to-Open Rate (CTOR) is an email marketing metric that measures how effective your email's content, design, and call-to-action are at driving clicks among the people who actually opened the message. Unlike the standard click-through rate (which divides clicks by total emails delivered), CTOR focuses only on engaged recipients — those who opened — making it a sharper gauge of content quality.
How to Use This Calculator
Enter the number of unique clicks (people who clicked at least one link) and the number of unique opens (people who opened the email) from your email service provider's report. The calculator divides clicks by opens and multiplies by 100 to give your CTOR as a percentage.
The Formula Explained
$$\text{CTOR} (\%) = \frac{\text{Unique Clicks}}{\text{Unique Opens}} \times 100$$ Using unique figures avoids inflating the number when one person clicks or opens multiple times. A higher CTOR signals that your subject line set accurate expectations and your email body delivered compelling, clickable content.
Worked Example
Suppose a campaign had 120 unique clicks and 500 unique opens. $$\text{CTOR} = \frac{120}{500} \times 100 = 24\%$$ That means nearly a quarter of everyone who opened the email also clicked — a strong result, since average CTOR across industries typically falls between 10% and 20%.
FAQ
What is a good CTOR? Most industries see 10–20%. Above 20% is excellent; below 6% suggests your content or call-to-action needs work.
How is CTOR different from CTR? CTR divides clicks by emails delivered, while CTOR divides clicks by opens. CTOR isolates content effectiveness from deliverability and subject-line strength.
Can CTOR exceed 100%? Not with unique values. If you use total (non-unique) clicks against unique opens it could, but the standard CTOR caps at 100%.
