What is Engagement rate?
Engagement rate is the ratio between a post’s interactions and the audience it reached. The most common calculation divides likes, comments, saves and shares by reach; the other divides by the number of followers. The first measures the quality of the content for those who saw it; the second measures how much the follower base responds. Because it is a percentage, it lets you compare a post that reached a thousand people with one that reached a hundred thousand, and compare your account with accounts of a different size.