Email Click-to-Open Rate Calculator
Click-to-open rate focuses on click activity among recipients recorded as opening an email. It is not the same as clicks divided by delivered emails.
How to use this calculator
- Enter unique clickers, unique opens using the same measurement window and units.
- Check the result and intermediate values, then change one input at a time when comparing scenarios.
- Keep the stated scope and assumptions attached to any result you share.
Formula and method
CTOR (%) = unique clickers ÷ unique opens × 100.
- The click-to-open rate is about 12.31%.
- Privacy protections and image prefetching can distort opens. The rate uses the supplied counts and is not a perfect measure of human attention.
Worked examples
Worked example
640 unique clickers and 5,200 unique opens.
The click-to-open rate is about 12.31%.
The click-to-open rate is about 12.31%.
Understanding the result
The click-to-open rate is about 12.31%.
Privacy protections and image prefetching can distort opens. The rate uses the supplied counts and is not a perfect measure of human attention.
Important notes
Privacy protections and image prefetching can distort opens. The rate uses the supplied counts and is not a perfect measure of human attention.
Use measured inputs or documented assumptions, and validate important decisions with the appropriate source specifications or professional guidance.
Frequently asked questions
Why use unique clicks?
Unique clickers reduce repeated-click inflation when measuring the share of recipients who clicked.
Should clickers exceed openers?
With unique-person counts from the same campaign, that is a warning to check definitions or tracking data.
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Related explanations
Learn the method behind the number or compare the terminology before using the calculator.
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This page provides a calculation tool plus explanatory information so you can understand what the result means and when the underlying method may not fit your situation.