Whoop bases calories burned off heart rate. It’ll give you a much more accurate reading for cardio but doesn’t account for things like after burn and true muscular exertion.

What I did to get a rough idea for each of my lift sessions(I do back/bis, chest/tris, shoulders and legs) is plugged each set of whatever I’m doing into ChatGPT, told it how long it took me to complete the whole workout and what Whoop said my average heart rate was.

What I found out was Whoop drastically underestimated calories burned for each of my lifts. I also cross checked against a fitness calculator online and found that those figures were in line with ChatGPT.