Tdee? Bmr? Bodymedia numbers?

Paul604

So I'm confused lol. Been doing great just eating healthy since January. Down 40+ lbs already. I got a bodymedia to help with watching calories and it really seems high. My daily average burned is around 3600. That's with little to no exercising. I am a big guy 6'3 currently around 240lbs. I have a decent amount of muscle hiding in there somewhere lol is that why I seem to burn more? I know the Bodymedia takes a few weeks to become more accurate. I'm eating around 1900 calories now and doing ok with that. Drop around 1lb or a little more per week. I just hope I'm not under eating. Trying to get back into working out. Usually do a 20 min jumping jack situp routine while at work at least 5 days a week. According to Bmf that burns about 150. I go for the odd run here and there. Trying to get back into it. Should I be eating more? I'm scared to cause the weight loss has been going pretty good over the last few months. If I go by my bodymedia I have a 1500-2000 calorie deficit daily. I just don't want to lose too much muscle mass. Going to get back in a gym soon so that will help. My tdee calculates out to 3168 sedentary. 3500ish working out 3 days a week. That means I would have to eat 2500-3000 calories a day and I'll have a 500ish deficit and I will still lose? Find that hard to believe. Thanks for any help