Engagement rate calculator
Three formulas share one name, and they give three different answers from the same post. This shows all three, so you know which number you are quoting and which one a brand will compute for themselves.
Which number should you quote?
By reach, and say so explicitly, because it describes your content rather than your follower history. Expect the brand to also compute by-followers from the outside, because that is the only input they can see — and expect it to be lower. Neither of you is wrong.
The part that matters more than the choice: use the same formula every time you compare anything. A rise from 2% to 3% means nothing if the first was by reach and the second by followers. The full guide covers why they diverge.
Nothing you type is uploaded, stored or logged — the maths runs in your browser.