Don't understand Calorie Needs Calculators
 

Okay, I have tried diff ones and they are similar. My baseline with "little activity" is 1500-1600 depending on the website.

If I change the setting to "Exercise 5x a week" my needs jump to 1900+. I don't see how exercising 5x a week can increase my caloric needs by 400 cal per day, for 7 days = 2800 additional calories.

That would mean I would need to burn 2800/5 exercise sessions = 560 calories per session, which would have to be about an hour of hard running or 1.5 -2 hours of more moderate exercise, according to activity calculators.

Is that what the "exercise level" drop down menus assume? Or is the after burn effect so much greater?

Instead, I have been going off the baseline 1500-1600, and then figuring I burn about 200 more for my little 30 minute video workouts.

My understanding is that the energy expenditure continues on after the workout is done depending on intensity and duration, with HIT elevating longest afterwards.