X engagement rate calculator
Formula: (likes + reposts + replies) ÷ impressions·Divided by: impressions·What is normal: 0.5% to 1% is typical, above 2% is very good
Impressions, which only the author can see
X shows impressions to the account that posted. Anyone computing your rate from outside is using follower count instead, which is why third party numbers about your account are usually wrong.
Replies are the expensive interaction
A like costs nothing. A reply costs attention, and it is the one that pulls the post back into other people's timelines.
Echoia does the rest: publishing to ten networks, every comment and message in one inbox. Free for three accounts.