# Open Rate

*Analytics*. The frequency by which your customers open emails that you send. To track opens, turn on [open tracking][open-tracking].

* To calculate the **Opens** percentage, divide the total number of times your users opened your emails by the total number of [delivered messages][delivery].
* To calculate the **Unique opens** percentage, divide the number of unique individuals that have opened your emails by the total number of delivered messages.

To learn more, see [Statistics](/docs/sendgrid/ui/analytics-and-reporting/stats-overview/).

[open-tracking]: /docs/sendgrid/ui/account-and-settings/tracking#open-tracking

[delivery]: /docs/sendgrid/glossary/deliveries