Email Open Rate

Email Open Rate is the percentage of people who open an email out of all the recipients.

This metric shows how well an email campaign grabs its audience’s attention.

It helps determine how many people on your email list are interested enough to click on and view the content of the email.1


email open rate formula

How Email Open Rate Is Calculated?

The email open rate is calculated by dividing the number of emails opened by the total number of emails sent (excluding those bounced) and multiplying the result by 100 to get a percentage.

The formula for the email open rate is:

Email Open Rate = (Number of Emails Opened / Total Number of Email Sent – Bounces) x 1002


The main reason for tracking the email open rate is to measure how well an email campaign engages recipients when they first receive an email.

It helps you understand how appealing your email subject lines are, whether the timing of your emails is effective, and how relevant your messages are to the people receiving them.3

Factors Influencing Email Open Rate

Several factors can influence the open rate:

  1. Subject Line: Compelling and relevant subject lines can significantly increase open rates.
  2. Sender Name: Recognition of the sender can influence a recipient’s decision to open an email.
  3. Timing: The time and day an email is sent can affect open rates, as certain times may align better with when recipients check their emails.
  4. Email List Quality: A well-segmented and targeted email list tends to yield higher open rates.
  5. Email Frequency: Over-sending can lead to email fatigue, whereas sending too infrequently might lessen your brand’s presence in the recipients’ minds.4


Here’s how the email open rate is used throughout various email marketing planning stages:


  • Targeting: By analyzing past open rates, you can segment your email list to more effectively target specific groups with content they’re likely to engage with, potentially boosting future open rates.
  • Subject Line Testing: Conducting A/B tests on different subject lines helps you find the ones that yield the highest open rates, allowing for optimization before the full campaign launch.

Campaign Launch:

  • Deliverability: Monitoring open rates during the campaign can indicate deliverability issues. For example, if many emails remain unopened, they might go to spam folders, suggesting a need to tweak how you send emails.

Post-Campaign Analysis:

  • Campaign Performance: Open rates help evaluate how successful an email campaign engages recipients. Comparing these rates across different campaigns can highlight which strategies worked best.
  • Identify Areas for Improvement: If open rates are low, it may signal that your subject lines aren’t effective or your content isn’t aligning well with your audience’s interests.5


Imagine an email campaign sent to 1,000 recipients, with 200 emails opened.

Assuming none of these emails bounced, the open rate would be calculated as follows:

email open rate calculation example

This 20% open rate can be analyzed against industry benchmarks, past campaign performance, or segmented audience responses to draw insights and guide future strategies.

Related Terms


1. What is email open rate?. Campaign Monitor. (2020, August 7).

2. Baggott, C., Sales, A. (2011). Email Marketing By the Numbers: How to Use the World’s Greatest Marketing Tool to Take Any Organization to the Next Level. Germany: Wiley.

3. Harbarczyk, I. (2023, December 24). How important is email open rate?. Bouncer.

4. Conceição, A., & Gama, J. (2019). Main factors driving the open rate of email marketing campaigns. In Discovery Science: 22nd International Conference, DS 2019, Split, Croatia, October 28–30, 2019, Proceedings 22 (pp. 145-154). Springer International Publishing.

5. Okugbe, O. (2023, August 7). 25 simple strategies to increase your email open rate. Adoric Blog.

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