Fitbit Calorie Adjustments

Fitbit crosses over so if you put it also in this app it gets doubled

Is there something illegal about an active person who has exercised burning 2500 Cal in a 24 hour day?

if your exercise was not step based (i.e. easy for Fitbit to interpret) and you also had your HR artificially elevated in comparison to your actual physical work (not perceived effort but actual total physical work actually performed regardless of how it felt at the time), then yes, that specific exercise as an isolated activity might be a bit over-inflated. And it would still be, what, a 2 hours span out of the 168 hours in a week?

However, 10K steps is firmly in the active category. And 10K steps plus exercise would be more. So I don't think that it is IMPOSSIBLE for even a "dainty little gal who can arm wrestle me to submission" to plausibly hit 2500 Cal in a day!

Is this a common day for you?

In the end you could / should probably average your 30 day Calories Out from Fitbit, 30 days of Calories in from MFP, compare to your weight trend change * 3500--I use trendweight.com connected to fitbit.com, and see how "accurate" the whole picture looks based on your individual circumstances. Even better if you're willing to make the effort... use rolling 4-6 week time periods to eliminate hormonal water retention. It is just easier to look at 30 days due to data export quirks.

In January with several eating out guesses my Fitbit - MFP balance would indicate that I ought to have gained weight equal to about 700 Cal. The scales indicated a 350 Cal loss during the month (154.8 to 154.7 weight trend)

Given that I'm dealing with, *at most*, a 3.33% error in terms of TDEE based on these figures, I'll call my recent "looser" logging and my Fitbit still well enough matched to make decisions with!

For me and the way I've logged, moved, and eaten during the past five years, my Fitbit TDEE has remained accurate to within 5% over any 30+ day span I've successfully measured.