Fitbit accuracy issues

I'm starting to really doubt my fitbit. I know it's all an approximation, but still...

Yesterday I walked 8.6 miles, did over 20,000 steps, climbed up 10 floors (ok probably more, but it doesn't register everything), had 38 very active minutes, and it says I burned 2190 calories. That can't be right. That's barely 100 calories above what Scooby tells me my TDEE is for lightly active! I had it off for 1 hour while I was doing a workout, but still, that just doesn't make sense... surely walking so much in a day puts me at least at moderately active?

Has anyone else noticed really weird results with fitbit?

Replies

  • Mokey41
    Mokey41 Posts: 5,769 Member
    Or you can look at it the other way that maybe the FitBit is accurate and the other calculations are off. I've often questioned the whole TDEE method because you're guessing on your perception of what lightly or moderately active is compared to whatever calculation they use to come up with a burn.
  • Francl27
    Francl27 Posts: 26,371 Member
    Yeah but that's the thing, I've done less exercise in the past and it said I had burned 2300 calories or more. Ok I was 4 lbs heavier, but still, it makes no sense.
  • SkinnyFatAlbert
    SkinnyFatAlbert Posts: 482 Member
    Or you can look at it the other way that maybe the FitBit is accurate and the other calculations are off. I've often questioned the whole TDEE method because you're guessing on your perception of what lightly or moderately active is compared to whatever calculation they use to come up with a burn.

    Aren't all calorie metrics just an estimate? Numbers just make people feel comfortable because people like to quantify things.
  • jenk7356
    jenk7356 Posts: 43 Member
    Go to the fitbit website and take a look at some of the question and answers and see if you find anything that helps. I actually was having issues and sent fitbit help an email. They helped me resolve my issues. Hope everything works for you.
  • rassha01
    rassha01 Posts: 534 Member
    Have you estimated your stride length correctly? I found this to me my biggest issue and once I got close I felt a lot more comfortable with the numbers it was giving me.
  • I_Will_End_You
    I_Will_End_You Posts: 4,397 Member
    I feel the same way about mine. I know I burn more calories than it says, because I'm losing weight and eating more than it says I burn.
  • Francl27
    Francl27 Posts: 26,371 Member
    Have you estimated your stride length correctly? I found this to me my biggest issue and once I got close I felt a lot more comfortable with the numbers it was giving me.

    I haven't found any way to do it. The mile number is correct though, as far as I can tell. I'm totally average (height, leg length etc) so usually whatever is default applies to me anyway.
  • beattie1
    beattie1 Posts: 1,012 Member
    Why did you take it off to do a workout? Was it aquarobics? You can add in thins like swimming and cycling on Fitbit's website. Otherwise I can't see why you'd take it off. Don't you want to get as accurate an ESTIMATE of your daily burn as possible?

    When I first got my Fitbit I was a bit taken aback by how little it gave me for exercise that I thought burned more, but I've got more or less used to it now. I still get a bit huffy when I complete my day's intake with, say 50 calories remaining, and by the end of the evening I'm in the red by a bit though I haven't eaten or drunk anything more.
  • DChabibi
    DChabibi Posts: 21 Member
    Figuring out the FitBit active minutes will be the death of me:(. There are days I do 1 hour of bootcamp then go for a dedicated 1 hour walk and I will have only 5 active minutes. Yesterday, I walked for an hour at lunch and then went for a 30 minute run/walk in the evening and had 22 active minutes. the most I've ever had since I bought the little thing in December. I have had days where I have gone for a dedicated 5 mile walk and had less than 10 active minutes at the end of the day. As you see, its a big puzzle and it blows my mind everyday. Sorry I couldn't be much help but wanted to let you know you are not the only one! :)
  • Francl27
    Francl27 Posts: 26,371 Member
    Why did you take it off to do a workout? Was it aquarobics? You can add in thins like swimming and cycling on Fitbit's website. Otherwise I can't see why you'd take it off. Don't you want to get as accurate an ESTIMATE of your daily burn as possible?

    When I first got my Fitbit I was a bit taken aback by how little it gave me for exercise that I thought burned more, but I've got more or less used to it now. I still get a bit huffy when I complete my day's intake with, say 50 calories remaining, and by the end of the evening I'm in the red by a bit though I haven't eaten or drunk anything more.

    It was Les Mills pump, it never registers at all as I pretty much don't move, so I just took it off so it wouldn't be in the way. I just know I burned 250ish more calories.

    What I don't understand is how it can give me 1900 calories if I walk 3 miles, but 2200 if I walk 8.6. It just doesn't add up.

    Mine isn't sync'ed with MFP though, I don't need that extra headache, lol.
  • Francl27
    Francl27 Posts: 26,371 Member
    Figuring out the FitBit active minutes will be the death of me:(. There are days I do 1 hour of bootcamp then go for a dedicated 1 hour walk and I will have only 5 active minutes. Yesterday, I walked for an hour at lunch and then went for a 30 minute run/walk in the evening and had 22 active minutes. the most I've ever had since I bought the little thing in December. I have had days where I have gone for a dedicated 5 mile walk and had less than 10 active minutes at the end of the day. As you see, its a big puzzle and it blows my mind everyday. Sorry I couldn't be much help but wanted to let you know you are not the only one! :)

    Yes, lol. Sometimes I just walk with the kids (so slowly) and I get some active minutes for that, but walking on the treadmill at 3.2mph with a 4% incline doesn't give me any...
  • Koldnomore
    Koldnomore Posts: 1,613 Member
    What I don't understand is how it can give me 1900 calories if I walk 3 miles, but 2200 if I walk 8.6. It just doesn't add up.

    Mine isn't sync'ed with MFP though, I don't need that extra headache, lol.

    It depends on a bunch of things, firstly your weight, second, the elevation, third, the speed. I do between 15-21k steps a day. Some days it will be all flat, others I'll do some hills or more stairs at work so it will change. It is totally possible to do what you feel is the 'same' and get different numbers. Also if you have had your FitBit for a while it will change with your weight because you don't burn the same number of calories as you used to when you were heavier so you will have to do more to achieve the same burn.

    The reason you may not get 'very active' minutes is because they require you to walk faster than normal, so if you just go for a 3 mile walk at a normal speed you may not get it. I have to push myself to get 'active' time - or at least that's what I find (my goal is 60min /day) and for 20k steps I JUST BARELY make it on most days. If your bar isn't 'green' you aren't active enough. As an example, I did 2 hours of walking last night and none of it was fast enough to qualify for 'very active' minutes.

    Calories are a ***** to burn..They don't come off easy. I did 12k steps Tuesday, 24k Wednesday and only burned @ 200 more calories. I'm 5'6 @ 160lbs currently.
  • Francl27
    Francl27 Posts: 26,371 Member
    I always update my weight on fitbit.

    I was 3 lbs heavier on Aug 24th, for example. It says I burned 2277 calories, with 17500 steps, 7.45 miles, 8 very active minutes, 12 floors.

    Yesterday, 2190 calories, 20500 steps, 8.64 miles, 38 very active minutes, 10 floors.

    I have a hard time believing that 3 less lbs would explain such a huge difference in numbers.
  • ShannonMpls
    ShannonMpls Posts: 1,936 Member
    What I don't understand is how it can give me 1900 calories if I walk 3 miles, but 2200 if I walk 8.6. It just doesn't add up.

    It's also quite dependent on what you did the rest of the day.

    If I go for a 6 mile run, then go to work but barely move all day because I'm spending the day writing, I'll burn about as many calories as if I spent a Sunday on my feet all day baking in my kitchen, but only go on a 3 mile walk. Some of my "rest" days result in a higher TDEE than a workout day because I spend them lightly active - shopping, cooking, playing with my son. It doesn't log a lot of steps but my fitbit knows I'm not sitting, sedentary all day. Your NEAT (non-exercise activity) matters more to your daily calorie burn than the 60 minutes or so that you dedicate to exercise.

    As for "highly active" minutes - that is based on calorie burn per minute, though I don't know the precise number Fitbit uses:
    https://help.fitbit.com/customer/portal/articles/1020095-what-are-"very-active-minutes"-

    A slow walk won't yield any very active minutes for me; neither will a yoga class. When I'm lifting weights in the gym, Fitbit doesn't count it as very active either unless I manually enter the exercise time using MFP.
  • jonnythan
    jonnythan Posts: 10,161 Member
    I'm starting to really doubt my fitbit. I know it's all an approximation, but still...

    Yesterday I walked 8.6 miles, did over 20,000 steps, climbed up 10 floors (ok probably more, but it doesn't register everything), had 38 very active minutes, and it says I burned 2190 calories. That can't be right. That's barely 100 calories above what Scooby tells me my TDEE is for lightly active! I had it off for 1 hour while I was doing a workout, but still, that just doesn't make sense... surely walking so much in a day puts me at least at moderately active?

    Has anyone else noticed really weird results with fitbit?

    What's your height/weight/age?
  • ShannonMpls
    ShannonMpls Posts: 1,936 Member
    I always update my weight on fitbit.

    I was 3 lbs heavier on Aug 24th, for example. It says I burned 2277 calories, with 17500 steps, 7.45 miles, 8 very active minutes, 12 floors.

    Yesterday, 2190 calories, 20500 steps, 8.64 miles, 38 very active minutes, 10 floors.

    I have a hard time believing that 3 less lbs would explain such a huge difference in numbers.

    Like I posted above, this can be easily explained by looking at your non-walking activity that day. Were you awake more on August 24? Did you spend a lot of time on your feet? If you went on an 8.64 mile walk but sat on your butt the rest of the day yesterday, yes - it definitely makes sense that you'd have burned more on the 24th than yesterday.
  • kibbets
    kibbets Posts: 2 Member
    I also have issues with my Fitbit that I don't really understand. I turned off the calorie prediction setting because I didn't wear the Fitbit for a week and that week it said I burned way more calories than I ever had while wearing it.

    It is still acting weird though.

    This week with everything on the same settings (i.e. my weight is the same and the calorie prediction is off), on Tuesday I had 5,661 steps and it says I burned 1,922 calories

    Then yesterday I had 6,846 steps and only burned 1,791.

    I really don't get how I can burn fewer calories from being more active.
  • jonnythan
    jonnythan Posts: 10,161 Member
    I also have issues with my Fitbit that I don't really understand. I turned off the calorie prediction setting because I didn't wear the Fitbit for a week and that week it said I burned way more calories than I ever had while wearing it.

    It is still acting weird though.

    This week with everything on the same settings (i.e. my weight is the same and the calorie prediction is off), on Tuesday I had 5,661 steps and it says I burned 1,922 calories

    Then yesterday I had 6,846 steps and only burned 1,791.

    I really don't get how I can burn fewer calories from being more active.

    More steps doesn't mean you burned more calories necessarily. Floors, speed, and other things factor into it. Also, if you logged any activities that will affect it as well.
  • kibbets
    kibbets Posts: 2 Member
    More steps doesn't mean you burned more calories necessarily. Floors, speed, and other things factor into it. Also, if you logged any activities that will affect it as well.

    It still doesn't make sense to me. I did not log any other activities either day. I did not climb any floors either day. And my walking both days were pretty identical except on Wednesday I was able to take walks during my breaks and on Tuesday I wasn't able to.
  • jonnythan
    jonnythan Posts: 10,161 Member
    More steps doesn't mean you burned more calories necessarily. Floors, speed, and other things factor into it. Also, if you logged any activities that will affect it as well.

    It still doesn't make sense to me. I did not log any other activities either day. I did not climb any floors either day. And my walking both days were pretty identical except on Wednesday I was able to take walks during my breaks and on Tuesday I wasn't able to.

    There was clearly something different, though without seeing your data it's tough to say what.
  • Francl27
    Francl27 Posts: 26,371 Member
    I always update my weight on fitbit.

    I was 3 lbs heavier on Aug 24th, for example. It says I burned 2277 calories, with 17500 steps, 7.45 miles, 8 very active minutes, 12 floors.

    Yesterday, 2190 calories, 20500 steps, 8.64 miles, 38 very active minutes, 10 floors.

    I have a hard time believing that 3 less lbs would explain such a huge difference in numbers.

    Like I posted above, this can be easily explained by looking at your non-walking activity that day. Were you awake more on August 24? Did you spend a lot of time on your feet? If you went on an 8.64 mile walk but sat on your butt the rest of the day yesterday, yes - it definitely makes sense that you'd have burned more on the 24th than yesterday.

    No it was the same. The mile total is all my walking during the day, including walks and pacing in the house and whatnot.
  • DChabibi
    DChabibi Posts: 21 Member
    OMG! I think I now have a handle on figuring out the active minutes. One of the guys-jonnythan- also posted something about speed that got me thinking. It is true...the faster you earn your 10K steps, the more active minutes you will have. I tested it out for about 3 days so I can make sure I totally got it. lol. So on Sat, went for an hour jog/run and got about 8k steps. Then I walked around a track afterwards to get to 10K. I did all this in a little less than 2 hours, maybe 1.30 hrs. The rest of the steps I earned for the day were from shopping or just walking around, not a 'dedicated' workout. I had about 38 active minutes that day. Most I've ever had since I owned the fitbit! I did something similar on Sunday and Monday and had about 30 active minutes each day. Yesterday, I did a walk at lunch and earned about 6K. The rest of the steps I earned during bootcamp class in the evening. I had only about 17 active minutes. So I was indeed earning the steps but it was spread out during the day so not per se super 'active'. Now I know!

    In terms of calories burned on FitBit... am still working on that. I don't have a HRM so I don't know if it calculates my calories burned on bootcamp days accurately. But hey one thing at a time.

    BTW, add me if you wish...http://www.fitbit.com/user/236Y3G