As another point of view, many calorie counters (including me) don't bother with calories burned, precisely for this reason - figuring out an accurate number is just too doggone hard!
I decided way back at the beginning of my weight loss journey that I would track calories in and get my deficit there (I wasn't aiming for a particular deficit for quite some time, just any deficit), and that all my exercise was going to be for fitness and overall health. Any boost it gave my weight loss was like a bonus.
That might not work for everyone, I know, but if you're going nuts trying to figure it out, it might be an option for you.