Engagement formula algorithm

What is the engagement algorithm of instagram? I want to manually calculate it and I cannot find any formula on google or I am just blind

Say you have a following of 2,500, your ‘engagement’ is measured by your likes and comments combined per post, divided by your following.

1 Like

Add the recent likes&comments from the latest (12) photos and divide by the number of photos added.

then take that number and divide it against your total followers.

Last 12 photos have 5400 likes and comments total
You have 50000 Followers

5400 / 12 => 450 average per photo

450 / 50000 => 0.009% Engagement

You could also just use this tool and skip the math


Also remember that the bigger your account gets, the engagement rates drops naturally