How accurate are your Fitbit calories?

Christismylife wrote: »

If you have a Fitbit (I have the charge 2) and have it sync to MyFitnessPal to calculate your daily exercise calories, how accurate do you find them to be?

I have my account set at the lowest activity level and my Fitbit syncs to add in exercise calories. I find the calories it gives me to usually be high compared to what I might have given myself for my exercise for the day. I wonder if this means the calculations are off or if I am more active most days overall than I realize.

When I had a Fitbit i checked it by comparing it to real time data and found it to be within 100 calories. It takes a few months of use and syncing (and meticulous logging) for it to be accurate,

The Garmin I have now is accurate to within 50 calories.

Christismylife wrote: »

If you have a Fitbit (I have the charge 2) and have it sync to MyFitnessPal to calculate your daily exercise calories, how accurate do you find them to be?

I have my account set at the lowest activity level and my Fitbit syncs to add in exercise calories. I find the calories it gives me to usually be high compared to what I might have given myself for my exercise for the day. I wonder if this means the calculations are off or if I am more active most days overall than I realize.

If your activity level is set to the lowest option, the Fitbit is giving you calories for more than just purposeful exercise. Basically anything you do during the day other than reclining or lying down will add up. You’ll get calories for walking to your car, folding laundry, standing for more than a couple of minutes, and grocery shopping, just for example.

That said: Fitbits are intended to be as accurate as possible...for walking. If you do a lot of other kinds of activity, it might be less accurate. I do a lot of indoor cycling, which my Fitbit always underestimates. If you drive on cobblestones, on the other hand, it’ll give you a suspiciously high rate of burn because it calculates steps based on jolting.

So try it for a month or two, see what happens to your weight when you eat what it tells you, and take things from there. 🙂

Mine underestimates. Either that or my metabolism is really much better than it should be. I mean, I was over by 400-800 calories consistently for almost a year and only gained 10 lbs...

I wear a Fitbit Charge 2 and find it pretty accurate. I eat back all or most of the exercise calories it gives me and have lost consistently.

I’ve been using Fitbit since 2013 (as well as a food scale) and I have found:

Non HR models (Zip, Flex, & Flex 2): underestimated by an average of 200 calories a day

HR models (Surge, Blaze, & Ionic): have been much closer (within 50-75 calories) when I ran the numbers. It’s been awhile since I ran through the numbers, but I have been pretty lazy with my tracking lately too. Really need to tighten up my logging for a few weeks and run the numbers again.

You may like to read this: http://berkeleysciencereview.com/fit-fitbit/

Consistency with how you use the data is what is important.

It's not just exercise, it's giving you back calories for all your activity even walking around or whatever you do during the day. Even as an office worker I still always got at least a couple hundred extra calories (without any actual exercise) and yes it was always pretty accurate as far as I could tell.

I also have the Fitbit charge 2. I read a study that says they're +- 20% innacurate if I remember correctly. Beats the whole point of having one right? Others are pretty much the same. I wouldn't adjust my calories based on its readings, you'll end up overeating if it's giving you high readings currently. I would just use it as a general indicator of whether you burnt more or less calories that day and +- how much.

etainwow wrote: »

I have a Garmin forerunner and I am really doubting the calories it gives me. How do you get it to track more accurately? I have MyFitnessPal set to my estimated BMR so that all calories clocked back through walking and excercise should be eaten. But it’s telling me to eat 2800 calories! I barely make 5k steps most days (very busy desk job and I’m trying to improve by walking on my 1/2 hour lunch break now) and I lift weights 3x a week. I’m definitely obese in my hip waist measurements (waist is 102 across my navel but my hips are 99! BMI 21). I want to lose fat and increase my lean muscle mass so I’m completely lost.

So you set your MFP eating goal to be your BMR estimate?

Since it's pace and weight that results in calorie burn, distance not steps is ultimately the important factor.

If you did or it thinks you did walk a big distance with 5K steps, and you weigh a lot - then big calorie burn for daily activity level of things.

If it shows in your Connect stats that it kept thinking you are doing workouts (if auto-workouts is enabled), and using HR-based calorie burn for low-level things - then inflated calorie burn.

While weight lifting using HR-based is inflated, 3 x weekly for 30-45 min is likely not that inflated.

Have you ever walked a known distance, high school track using correct markings for 1/2 mile or more, to confirm it reports the correct distance?
Might have to adjust stride length. And it should be avg daily pace, not grocery store shuffle, not exercise level pace.

I'm using the daily burn data from my charge two and my MFP logging to calculated theoretical weight loss. And then comparing that to my actual loss. I'm coming in with a difference of around 20kcals per day (using data from the last 4 months).

So, yeah, for me it's pretty accurate.