Burning calories doing calisthenics

It's a little too cold outside to start running again, so I do the following:

I alternated 4 sets of 5 reps on the ab-wheel with 4 sets of 10 6-count body builders (from a standing position: 1) Squat, 2)thrust legs out behind you (push-up/ plank position), 3) down push-up position, 4)plank, 5) squat position, 6) stand.

The goal is to increase both the ab-wheel reps and the 6-counts reps, ans well as the number of sets. Both of these exercises really raise the heart rate, much like doing wind-sprints. At least, it feels like I've done several wind sprints.

I'd like to have an jonest assessment of these types of exercises. How many calories am I burning? As I get more comfortable doing these things, I'll incorporate more exercises and probably some resistance.