Open Rate Defined

Open rate is expressed as a percentage. The formula for calculating open rate is:

Open Rate (%) = (Unique opens / Number of delivered emails) x 100

Unique opens (as opposed to "opens") is a metric that counts each individual recipient only once, even if they re-open an email multiple times. Your number of delivered emails should be provided by your Email Service Provider in your email marketing solution.

Using the formula above, if 500 people successfully received your email and 25 of them opened it, your open rate would be 5%.

Open Rate (5%) = (25 / 500) x 100

There are a variety of factors that can impact your open rate, including:

• The quality of your email list: A high-quality email list consists of engaged subscribers who have opted-in to receive emails from your brand. If you're sending emails to users who are unengaged, have unsubscribed, or never provided opt-in permission, then your open rate will suffer. Regularly cleaning your email list is important to maintain list quality.
• The subject line and preheader: The subject line and preheader of an email are the first, and sometimes the only thing, that a recipient sees in their inbox. If these elements don't resonate with the recipient, then chances are they won't open your email. Learn 10 tips for writing more effective email subject lines and preheaders.
• The sender name: As a general rule, email recipients are more likely to open an email from a sender they recognize and trust. Ensure your sender name and email branding are consistent across your email campaigns and other channels to help nurture that quick recognition.
• The timing: When you send an email can impact how likely it is to be opened. For instance, if you send a professional email at 11 pm on a Friday, there's a chance it will get buried in a recipient's inbox before they're back at work Monday morning. To perfect your timing, it's important to segment your audience list so you can localize message send time by region. You can also personalize your timing based on each recipient's historical behavior using tools like OneSignal's Intelligent Delivery feature, which automatically sends messages when each users is most likely to be engaged.
• The email frequency: Sending too many emails in short succession can lead to email fatigue and decrease your open rates. As you plan your email campaigns, be mindful of the total number of communications you're sending, including transactional messages and emails from other campaigns. Some customer engagement solutions provide a built-in failsafe against over-messaging, like OneSignal's Frequency Capping feature. Although it's easy to keep track of message frequency at an early growth stage, as you scale up your marketing and engagement strategy and grow your company, more teams may regularly send communication to customers.

What's considered a "good" email open rate varies by industry and email type. Many companies consider 20% as a good email open rate benchmark to evaluate success.

Companies with more brand recognition and bigger email lists have different barometers of success than startups with smaller audiences. Similarly, some industries are known to have higher email open and click-through rates than others. As you analyze your campaigns, check out email benchmarks for your industry to help contextualize your analysis.

The type of email you send can also impact your open rate. Transactional emails often have higher open rates than promotional messages because they contain critical and often urgent information that a recipient needs or wants (ex: password reset emails). Transactional emails can have an open rate of 50%, whereas promotional emails are considered to be successful if they have an open rate of 15-20%. Learn more about the difference between transactional and promotional messages and view key examples by industry.

SMS marketing is known for its exceptionally high open rates. SMS open rates can be as high as 98%, whereas email open rates are typically around 20%.

Similar to email, what's considered a "good" open rate is highly contextual to the industry and type of content being sent. It's also worth noting that the goal of SMS marketing is not just to get a high open rate but to drive engagement and conversions. Click-through rates, conversion rates, and other KPIs can provide a more informed picture of the success of an SMS marketing campaign.

Read more about when to use email, SMS, and other communication channels to further hone and optimize your cross-channel engagement strategy.