Engagement rate is the percentage of audience who liked or commented on your content. It gives you insight into how active your audience is and what’s working best for you on Instagram.
Engagement rate of a single post is calculated as the sum of likes and comments divided by the number of followers you had at the time of the post publication.
It is also useful for benchmarking your own performance against your competitors. Engagement per follower allows you to compare Instagram accounts of different sizes.