What is click-to-open rate?
Click-to-open rate, or CTOR, is the share of people who opened an email and then clicked. By looking only at openers, it isolates how engaging the content and offer were, separate from how many people opened in the first place. It answers a different question than click rate. Click rate asks how many recipients acted; CTOR asks how many of the interested ones did.
The CTOR formula.
CTOR = (unique clicks divided by unique opens) times 100. Both should be unique counts, so the rate reflects people rather than repeat actions. Because opens sit in the denominator, anything that distorts opens distorts CTOR. That is the metric\u0027s main weakness today.
A worked example.
An email gets 400 opens and 50 clicks. CTOR is 50 divided by 400, times 100, which is 12.5%.
What is a good CTOR?
CTOR often lands in the 10 to 20% range, but a caution applies: Apple Mail Privacy Protection inflates opens, which pushes CTOR down for lists with many Apple Mail users. Read the trend over time rather than chasing an absolute number, and compare campaigns of the same type.
How to improve it.
Match the body to the promise of the subject line, make the call to action obvious, and design for easy tapping on mobile. The opener is already interested, so the content just has to deliver.