Accuracy?

So lately I've found myself wondering if my fitbit is accurate? I used to think that it most likely overestimated calories burns but now I'm wondering if it could possibly be the opposite? From what I have read 20,000 steps is considered active/very active. Yesterday I walked 30,170 steps (220 active minutes) and my fitbit says that I burned 2,533 calories. When I calculated my tdee it is saying that I burned 2,607 calories, but that would be if I estimated for 20,000 steps a day? So should my burn actually be even higher than that? Does anyone find that their fitbit under estimates their calorie burn? Do you think that mine is giving me an accurate calorie burn?

Replies

NancyN795

Mine seems to be very close to right, but everyone is different. The only real way to know is over time, with accurate food logging. If you lose at the predicted rate, it is accurate, if you lose faster, it underestimates, if you lose more slowly than predicted, then it overestimates.

I'm just guessing, but the 2533 calories for 30K+ steps does seem kind of low.

editorgrrl

alliesgettinghealthy wrote: »

Does anyone find that their fitbit under estimates their calorie burn? Do you think that mine is giving me an accurate calorie burn?

The only way to gauge the accuracy is to trust your Fitbit for several weeks, then reevaluate your progress.

heybales

alliesgettinghealthy wrote: »

So lately I've found myself wondering if my fitbit is accurate? I used to think that it most likely overestimated calories burns but now I'm wondering if it could possibly be the opposite? From what I have read 20,000 steps is considered active/very active. Yesterday I walked 30,170 steps (220 active minutes) and my fitbit says that I burned 2,533 calories. When I calculated my tdee it is saying that I burned 2,607 calories, but that would be if I estimated for 20,000 steps a day? So should my burn actually be even higher than that? Does anyone find that their fitbit under estimates their calorie burn? Do you think that mine is giving me an accurate calorie burn?

Your Fitbit seeing all your steps (and hopefully accurate) and estimating calorie burn - or you picking from 5 rough levels based on hours or days a week of exercise.

I suppose you could luck out and hit exactly what it says, but obviously there is a whole lotta range between levels for calories.

It should underestimate for the following reasons.
All non-moving time is giving sleeping level calorie burn, called BMR.
- But when awake you burn more, called RMR.
- When standing not moving you burn more.
- When digesting/processing food you burn more, about 10% of calories eaten.

All those things are unaccounted for, making your actual calorie burn higher.

But perhaps it balances out bad food logging that is usually underestimated by general public doing memory logging methods.
MFP helps with that aspect.

It's very difficult to estimate calorie burn from purely steps, as that is as far away from calories as you can get.
Fitbit uses steps to estimate distance. Now with distance and time and mass you can get good estimate of calorie burn.
Because you can take slow shuffle steps or serious walking steps, and burn different amounts in reality, and Fitbit tries to figure that out, actually pretty decently.