Engagement rate

Engagement rate expresses interactions as a share of reach: likes, comments, shares and saves over either views, impressions or followers, depending on who is doing the sum. Because no two platforms pick the same numerator or the same denominator, a 6% rate on one network and a 6% rate on another describe different behaviour. Media kits exploit that. A creator quoting engagement rate against followers will always look stronger than one quoting it against impressions, and neither figure is wrong. Ask which formula produced it before you compare anyone to anyone.