Fitbit Zip

I just got a Fitbit Zip & I'm still learning to use it. When I entered my Zumba activity for 50 minutes based on my height, weight and age that I entered on the Fitbit website, it states that I burned 332 calories. However, when I entered the same exact information in MFP, it states that I burned 737 calories. Which one is correct? I'd like to think the higher one is, but I want to be as accurate as possible. Any help would be greatly appreciated!