When to use this calculator
Measure email clicks relative to unique opens rather than delivered emails. Email privacy features and automated opens can distort the denominator.
Explore the marketing & customer calculators for other questions in this topic. For a related calculation, use the Conversion Rate Calculator: Find what percentage of visitors complete a chosen action.
PUTTING IT INTO PRACTICE
Click to Open Rate: a worked example
The values below are an illustrative example, not a recommendation. Replace them with measurements or assumptions that match your question.
| Input | Example value |
|---|---|
| Unique clicking recipients (integer) | 80 |
| Unique opening recipients (integer) | 400 |
| Result | 20 % |
- Check the input labels and enter the example values above.
- Apply the relationship: CTOR (%) = unique clickers/unique openers × 100.
- The result is 20 %, rounded for display.
How to interpret your result
Email privacy features and automated opens can distort the denominator.
Define the event, audience and attribution window before calculating a rate. Clicks, customers and orders are different units. Acquisition cost and campaign CPA may cover different spending categories.
Frequently asked questions
Should I count unique users or total events?
Use the definition matching your metric. State it consistently because repeat events can produce a different rate from unique people.
When is the click to open rate calculator useful?
Measure email clicks relative to unique opens rather than delivered emails. Email privacy features and automated opens can distort the denominator.
How do I use the click to open rate calculator?
Enter unique clicking recipients (integer), unique opening recipients (integer). The result updates automatically. Use the units shown beside each input; the example values illustrate the method.
Which formula does this calculator use?
CTOR (%) = unique clickers/unique openers × 100.
What should I check before using the result?
Email privacy features and automated opens can distort the denominator.
How are results rounded?
Scalar numbers display up to six decimal places, with scientific notation for very large or small values. Text, fraction, date and schedule outputs use the format described on the tool. Intermediate calculations use JavaScript floating-point arithmetic. Keep sensible precision for your measurements.
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