The number of calories that you burn during any physical activity depends on a lot of factors, including your weight, height, age, etc. As for crunches, you may wonder how many calories you burn doing these exercises. I recommend reading the article here https://betterme.world/articles/how-many-calories-do-you-burn-doing-crunches/. It will provide you with detailed info on the topic.
It's a question many of us could ask. More than 45 million Americans now belong
to a health club, up from 23 million in 1993. We spend some $19 billion a year
on gym memberships.
People who regularly exercise are at significantly lower risk for all manner of
diseases — those of the heart in particular. They less often develop cancer,
diabetes and many other illnesses. But the past few years of obesity research
show that the role of exercise in weight loss has been wildly overstated.