How do I know how many calories I am really burning?

Kel3369

Help!

My pedometer says one thing, this site says another, the machine I use has a third value, and various websites also have different numbers. I have been doing the 30 day shred DVD with Jillian Michaels and I don't know what to count it as so I have said it is 20 minutes of low impact aerobics when I enter it in here, but that's not really accurate because there is floor work and it's not all aerobic. Also, when I walk outside my pedometer tell me a different amount of calories burned than what is said when I try to log it here at MFP. How do you guys figure this out? If I am wrong this could really hurt my bottom line because I need to stay accurate as possible to my calorie goals. Anyone know what I should do? So far, I look at all of them and take the lowest value to be safe. Is this the best way to do this? Thanks so much!