Open Rate Calculator

We have provided a useful online Open Rate Calculator below to work out the Open Rate of your email campaigns. You can also derive the number of people you need to open your email in order to hit a target Open Rate, as well as the number of delivered emails.

Feel free to experiment with different scenarios using our Open Rate Calculator in order to help you better understand this metric.



What is Open Rate?

Open Rate is a metric used in email marketing. It is used to show the percentage of people who opened an email out of everyone who actually received it.

Occasionally abbreviated to OR, Open Rate is a powerful way to compare the performance of some of the meta-variables of email campaigns, such as subject line, preview snippet, and the time when an email is sent.

Getting people to open your emails is a challenge almost as large as writing a successful email itself, so by monitoring email open rate you can see if you are making your email enticing enough from the outset.


Why Use Open Rate?

Open Rate is a much better measure than just Opens as it helps you to compare email campaigns of different sizes. Take a look at this example:

Email ONE – delivered 21,000 times but only opened by 2,131 people.
Email TWO  – delivered 7,000 times but only opened by 1,024 people.

As you can see, Email ONE was both delivered to, and opened by far more people. This higher number of opens makes it seem like a better email. However, Email ONE was also delivered to times more people, so it had three times more opportunity for opens. If you multiply the number of people who opened Email TWO by three, it actually has more! This is a simple example of why opens aren’t a good measure alone.

By using Open Rate instead, we can see that Email ONE had an Open Rate of 10.15%, while Email TWO (while smaller) had an Open Rate of 14.63%. This means that people who received Email TWO were generally more convinced to open that email, than those who received Email ONE.

As with all email marketing metrics, Open Rate shouldn’t be looked at in isolation. CTOR and Conversion Rate are vital to see whether an email clicked on after opening it, and what happened after the clicks.


Open Rate Formula

The Open Rate equation is:

Open Rate Formula for our Open Rate calculatorClick to enlarge

Open Rate = (Opened x 100) ÷ Delivered


Find out more


Back: Ad Calculators