How to use this calculator
- Enter or choose emails delivered.
- Enter or choose unique opens.
- Enter or choose unique clicks.
- The click-to-open rate updates as you type. Use Copy result or Share to keep it.
Method
CTOR = Unique clicks ÷ Unique opens × 100; Open rate = Unique opens ÷ Delivered × 100; Click rate = Unique clicks ÷ Delivered × 100
- Unique opens
- recipients who opened (CTOR denominator)
- Delivered
- emails that did not bounce (open- and click-rate denominator)
Worked example
- CTOR = 300 ÷ 2,500 × 100 = 12%.
- Open rate = 2,500 ÷ 10,000 × 100 = 25%.
- Click rate = 300 ÷ 10,000 × 100 = 3%.
300 clickers among 2,500 openers is a 12% click-to-open rate; 3% of all delivered recipients clicked.
What the result means
Open rate reflects the subject line and sender; CTOR reflects the content once opened. A high open rate with a low CTOR suggests the email did not deliver on its subject line.
Assumptions and limits
- Opens and clicks are unique (each recipient counted once).
- Privacy features such as Apple Mail Privacy Protection record opens automatically, inflating opens and lowering CTOR. Click-based metrics are more reliable.
Questions
Why can someone click without an open being recorded?
If images are blocked the open pixel never loads. Most email platforms count a click as an open, which is why clicks cannot exceed opens here.