How to Calculate Your Email Open Rate For Free

A image with a gmail icon and the text How to Calculate Email Open Rates For Free

In an era where social media platforms come and go like fashion trends, email marketing remains the little black dress of the digital world—timeless, essential, and incredibly versatile. It's a direct line to your audience, offering a personal touch that other platforms can't match.

But what good is sending out emails if no one is opening them? That's where tracking email open rates comes into play. This metric serves as the pulse of your email marketing campaign, indicating how well your messages resonate with your audience. A low open rate could signal that your emails are getting lost in the shuffle or, worse, ending up in the recipients' spam folder. On the other hand, a high open rate is a green light, telling you that your subject lines are catchy, and that your content is engaging. And with the right mail tracker, you'll have real-time data and insights into how your emails are performing.

Knowing your email open rate is essential if you want to work in a data-driven way. A/B testing, benchmarking, and email optimization would all be impossible without knowing it. So in this article, we’ll dive into email open rates and why you should care about them. And we’ll also take you through the process of finding the data you need to calculate it 

What is an Email Open Rate?

Your email open rate is a metric that measures how many of the emails you send are being opened. You calculate it by dividing the number of email that are opened by the number of emails you send out and multiplying the result by 100. So if you send out 5 emails and 1 of them gets opened, your email open rate is 20%

An email open rate serves as a health indicator for your email marketing campaigns. It's the first hurdle in the customer engagement journey. If your emails aren't being opened, then your content, calls-to-action, and offers are all for nothing. In essence, a high open rate signifies that your subject lines are compelling and your email list is engaged, while a low open rate is a red flag that indicates you need to change something.

How High Should Your Open Rate Be?

While open rates can vary widely depending on the industry, the type of email, and various other factors, there are some general benchmarks to aim for:

  • B2B Industry: Around 15-25%

  • Retail: Approximately 20-30%

  • Nonprofits: Roughly 20-25%

  • Healthcare: About 15-20%

But ultimately, your specific situation might differ wildly from these benchmarks. The most important benchmark you can use is your own past performance. If you’re doing better than you used to, that’s growth!

How Can Email Trackers Help?

To calculate your open rate, you need to know if your emails are being opened. And to know that, a free email tracker can be a handy tool. Email trackers notify you when your emails are read. 

Mail trackers work by embedding a tiny, invisible image or pixel into your outgoing emails. When a recipient opens the email, the image is downloaded, triggering a notification back to the mail tracker. This process allows you to receive real-time data on when, and sometimes even where and on what device, your email was opened. 

The Formula for Calculating Your Email Open Rate

To calculate your email open rate, you need the following formula:


As you can see, you’ll need some data for the open rate formula. Figuring out how many emails you sent out is usually fairly easy. You can go into your sent emails and count them, or use an app to track them. The other data point used to be more difficult. Previously, only expensive email CRM’s like Hubspot or Mailchimp could help you track if your emails were being opened. But nowadays, free email trackers like Mail Track make it easy to get that data. And if you don’t feel like calculating it yourself, you can easily find an online calculator to do it for you.

A Step-by-Step Guide to Calculating Email Open Rate

  1. Gather Data: Use the Mail Track extension for Gmail to find out how many emails you sent out and how many of them were opened.

  2. Plug into Formula: Plug the data into the formula or an online calculator.

  3. Interpret the Result: Now that you have your open rate, compare it with your past open rates. If it’s low, find out what you can improve. And if it’s high, try to find out what specifically you’re doing right. 

How to Improve Your Email Open Rates

If you find that your open rate isn’t as high as you’d want it to be, don’t worry. Email marketing is a recursive process and successful emails aren’t born, they’re crafted over time. So to help you along, here are some factors you can play around with to increase the open rate of your emails.

A/B Testing

A/B testing is the marketing equivalent of a science experiment. Create two versions of your email with one key difference—perhaps it's the subject line, the call-to-action, or even the image used. Send each version to a subset of your audience and monitor which one performs better in terms of open rates. The real-time data from your mail tracker can make this process even more efficient.


People open emails that feel tailored to them. Use the recipient's name, reference past interactions, or segment your email list to send more targeted content. Personalization means more than just saying “Hi, [Name]”. You have to deliver value that feels custom-made for the recipient.

Timing and Frequency

Timing is everything, they say, and they're not wrong. Sending your emails when your audience is most likely to be checking their inbox can significantly improve open rates. Similarly, the frequency of your emails matters. Too many, and you risk annoying your audience; too few, and you become forgettable. Finding the right balance is key, and this is where analytics from your mail tracker can provide invaluable insights.

In the end, the best way to a good email flow is experimentation and data. You’ll have to take care of the experimentation part yourself, but we can help you with gathering the data. Mail Track is an email tracker for Gmail, that inserts the well-known “read” receipt into your emails. This way, you know whether your emails are being read or not. You can even find out how many times your e-mails are opened, and at what times. Mail Track works on your Android, iPhone, PC or Mac. So no matter your setup, we can help you calculate your open rate. Give us a try, it’s free for as long as you need :).