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Email Open Rate & Click-Through Rate Calculator

Calculate the open rate, click-through rate, and click-to-open rate of an email marketing campaign.

Result

Open Rate
22%
Click-Through Rate (CTR)
3.3%
Click-to-Open Rate
15%

About the Email Open/Click Rate

This calculator produces the three core engagement metrics for an email campaign at once: open rate, click-through rate, and click-to-open rate. It's built for marketers evaluating whether an email's subject line, content, and calls to action are performing, using only the delivery, open, and click counts already available in any email platform's reporting.

How It Works

You enter emails delivered, unique opens, and unique clicks for a campaign. The calculator divides opens by emails delivered for open rate, divides clicks by emails delivered for click-through rate, and separately divides clicks by opens for click-to-open rate, each expressed as a percentage.

openRate = (opens / emailsDelivered) x 100; CTR = (clicks / emailsDelivered) x 100; clickToOpenRate = opens > 0 ? (clicks / opens) x 100 : 0

Examples

Standard newsletter send

A campaign delivered to 10,000 addresses with 2,200 unique opens and 330 unique clicks yields an open rate of 22.0%, a click-through rate of 3.3%, and a click-to-open rate of 15.0% (330/2,200).

High opens, weak content engagement

A campaign delivered to 5,000 addresses with 1,800 unique opens but only 90 unique clicks has a strong 36.0% open rate, but a click-through rate of just 1.8% and a click-to-open rate of 5.0%, pointing to a subject line that worked while the email body or offer did not.

Advantages

  • Calculates all three standard email engagement metrics from a single set of inputs, avoiding manual division errors across reports
  • Separates click-to-open rate from click-through rate, isolating content performance from subject line performance
  • Uses the same delivered, opens, and clicks figures already shown in most email service provider dashboards, so no extra data pulling is needed

Common Mistakes

  • Judging content and calls to action using click-through rate alone, when a low CTR paired with a strong open rate points to a content problem, not a subject line problem
  • Comparing open rates across campaigns sent to lists of very different engagement levels without accounting for list quality differences
  • Using total opens or total clicks (which count repeat opens and clicks) instead of unique opens and unique clicks, inflating all three rates

Edge Cases to Watch For

  • If emails delivered is zero or negative, the calculator returns an error, since both open rate and CTR require a positive delivered count as the denominator.
  • Click-to-open rate is set to 0 whenever unique opens is zero, avoiding a division by zero while still returning a valid result for the other two metrics.
  • The calculator uses unique opens and unique clicks as entered; it does not deduplicate or validate these against delivered count, so entering opens or clicks higher than emails delivered will still compute (and can produce rates above 100%).

Common Use Cases

  • An email marketer benchmarking a single campaign's performance against past sends
  • A content team diagnosing whether a weak campaign result stems from subject line, content, or call-to-action issues
  • Anyone reporting standardized email metrics to stakeholders who need open rate, CTR, and click-to-open rate side by side
Written & fact-checked by the Calculateus TeamLast updated August 5, 2026How we verify our formulas

Frequently asked questions

What's the difference between CTR and click-to-open rate?

Click-through rate is calculated against all emails delivered, while click-to-open rate is calculated against only the emails that were actually opened - click-to-open rate isolates how compelling your content and call-to-action were, once you've already gotten the subscriber to open the email.

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Conclusion

Looking at open rate, click-through rate, and click-to-open rate together separates two different jobs an email has to do: getting opened and getting clicked. Use the split to target the right fix, whether that's the subject line, the send time, or the content inside the email itself.