Fitbit Calorie Burn

ICameToGetDown
ICameToGetDown Posts: 958 Member
edited November 26 in Health and Weight Loss
How accurate is your Fitbit for calorie burn? I have the charge HR and am trying to calibrate what it reports vs actual.
For example, this past week, my calories in vs out was -11,197, but I only lost 2.3. My logging should not be off more than 10%.
Any learnings would be helpful :-)

Replies

  • WBB55
    WBB55 Posts: 4,131 Member
    I took an inch of my height on the settings, and now I find that the long term accuracy (based on very detailed logs for months and months) is +/-70 calories per day (which I suppose might be accounted for in my vitamins and medications). The only exercises it doesn't work for is swimming and biking (though, I have the One).
  • LovingLife_Erin
    LovingLife_Erin Posts: 328 Member
    I've had mine almost a year and find it to be pretty accurate. I seem to lose pretty close to what I should lose based on the math.
  • Abby2205
    Abby2205 Posts: 253 Member
    One week is not a long enough period to analyze for meaningful conclusions. I analyzed my data over 14 weeks (it was a good stretch where I logged faithfully every day and wasn't eating out much so I didn't have a lot of really uncertain entries) and found that my Fitbit One burn corresponded very well to calorie intake and weight lost.
  • Pawsforme
    Pawsforme Posts: 645 Member
    I think mine is pretty accurate.
    But keep in mind that both calories consumed and expended are estimates.
    Make sure you have your stride length set accurately.
    I wear mine on my non-dominant hand but set it so that it thinks it's on m dominant hand. I believe that helps improve accuracy and keep it from inadvertently recording steps when I'm typing, cooking, etc.
    Keep in mind that the discrepancy you're seeing may be due to water weight fluctuation.
  • anichole2679
    anichole2679 Posts: 4 Member
    I have a client who wears a polar and a Fitbit. While doing any type of cardio that no at a steady pace like a group fitness class she will look at both and notice a few hundred calorie burn difference between the two and every time the reason is bc the Fitbit was showing no heart rate. The Fitbit has great features that the polar does not so this is why she wears both. She looked this up to see if others were having the same issue and they are.
  • tiffkittyw
    tiffkittyw Posts: 366 Member
    WBB55 wrote: »
    I took an inch of my height on the settings, and now I find that the long term accuracy (based on very detailed logs for months and months) is +/-70 calories per day (which I suppose might be accounted for in my vitamins and medications). The only exercises it doesn't work for is swimming and biking (though, I have the One).

    Thank you for that tip! I have hypothyroidism and I always heard to subtract 200 calories from what your Fitbit says you burned, but now I just changed it from 5'4" to 5'3" so maybe now I can just go off of what it tells me.

  • ICameToGetDown
    ICameToGetDown Posts: 958 Member
    I will continue to track. It has not been close since I got the Fitbit three weeks ago.
    Thanks for the info on the height. I didn't realize you input your stride.
  • mrsnazario1219
    mrsnazario1219 Posts: 173 Member
    edited November 2015
    How accurate is your Fitbit for calorie burn? I have the charge HR and am trying to calibrate what it reports vs actual.
    For example, this past week, my calories in vs out was -11,197, but I only lost 2.3. My logging should not be off more than 10%.
    Any learnings would be helpful :-)

    Do you have it set to negative??

    Btw.. I'm from central NJ :)
  • 3dogsrunning
    3dogsrunning Posts: 27,167 Member
    Am I correct in assuming you were to expecting to lose just over 3 lbs? You lost almost 2.5.
    Things to remember - this is all just an estimate, regardless of how diligent you log and track. 3500 lb / fat is an estimate. You also don't lose pure fat when you lose weight.
    Also, the scale doesn't show the whole picture. There are numerous other factors that affect scale weight. Hormones, food intake, glycogen stores, hydration levels, etc.
  • daniwilford
    daniwilford Posts: 1,030 Member
    I kept a spread sheet for three months before syncing my fitbit to MFP. I still keep the spread sheet. Measuring CO with fitbit and CI from MFP and calculating a 3500 calorie deficit per pound, my loss is 95% accurately predicted. In the beginning my loss was usually higher than predicted, in the last month my loss has been lower than predicted more often than higher but still 95% accurate.
  • Pawsforme
    Pawsforme Posts: 645 Member
    tiffkittyw wrote: »
    WBB55 wrote: »
    I took an inch of my height on the settings, and now I find that the long term accuracy (based on very detailed logs for months and months) is +/-70 calories per day (which I suppose might be accounted for in my vitamins and medications). The only exercises it doesn't work for is swimming and biking (though, I have the One).

    Thank you for that tip! I have hypothyroidism and I always heard to subtract 200 calories from what your Fitbit says you burned, but now I just changed it from 5'4" to 5'3" so maybe now I can just go off of what it tells me.

    If you're on medication and your numbers are good being hypothyroid shouldn't affect your calorie burn. I'm hypothyroid and as well as I can tell my Fitbit is quite accurate.
  • tiffkittyw
    tiffkittyw Posts: 366 Member
    Pawsforme wrote: »
    tiffkittyw wrote: »
    WBB55 wrote: »
    I took an inch of my height on the settings, and now I find that the long term accuracy (based on very detailed logs for months and months) is +/-70 calories per day (which I suppose might be accounted for in my vitamins and medications). The only exercises it doesn't work for is swimming and biking (though, I have the One).

    Thank you for that tip! I have hypothyroidism and I always heard to subtract 200 calories from what your Fitbit says you burned, but now I just changed it from 5'4" to 5'3" so maybe now I can just go off of what it tells me.

    If you're on medication and your numbers are good being hypothyroid shouldn't affect your calorie burn. I'm hypothyroid and as well as I can tell my Fitbit is quite accurate.

    I just started the meds at the end of October so I won't know until my next lab work in December if I'm on the right dose of medication.
  • Christine_72
    Christine_72 Posts: 16,049 Member
    WBB55 wrote: »
    I took an inch of my height on the settings, and now I find that the long term accuracy (based on very detailed logs for months and months) is +/-70 calories per day (which I suppose might be accounted for in my vitamins and medications). The only exercises it doesn't work for is swimming and biking (though, I have the One).

    Is changing your height necessary? Will this make the fitbit more accurate? I'm still struggling to trust it and eat back 100% of my calories earned...
  • pineygirl
    pineygirl Posts: 322 Member
    edited November 2015
    I don't think mine is accurate at all. It says I burn from 2200 to 2850 calories per day. Average is around 2400. I'm 5'1 and 125lbs. I have it on my non dominant hand but set to dominate so it's not picking up that many extra fake steps.

    Um...no. Just no. I have hypothyroidism and PCOS. No way I could burn that much at my size and age. I only take about 18,000 steps a day. I work on my feet all day and have a 1 year old son. So I'm lightly active plus a little exercise. I leave a 200 to 350 calorie "buffer" in addition to my 500 calores deficit that's built in.

    So far it's sort of working. I lost 3lbs in 3 weeks.

    I'm also from NJ....debatable if it's Central or South though....
  • 3dogsrunning
    3dogsrunning Posts: 27,167 Member
    pineygirl wrote: »
    I don't think mine is accurate at all. It says I burn from 2200 to 2850 calories per day. Average is around 2400. I'm 5'1 and 125lbs. I have it on my non dominant hand but set to dominate so it's not picking up that many extra fake steps.

    Um...no. Just no. I have hypothyroidism and PCOS. No way I could burn that much at my size and age. I only take about 18,000 steps a day. I work on my feet all day and have a 1 year old son. So I'm lightly active plus a little exercise. I leave a 200 to 350 calorie "buffer" in addition to my 500 calores deficit that's built in.

    So far it's sort of working. I lost 3lbs in 3 weeks.

    The fitbit doesn't know that and doesn't take that into account. It is based on an average person with no medical issues.
  • ForecasterJason
    ForecasterJason Posts: 2,577 Member
    I think my Fitbit may slightly overestimate my calories, but overall I think it is pretty close.

    pineygirl wrote: »
    I don't think mine is accurate at all. It says I burn from 2200 to 2850 calories per day. Average is around 2400. I'm 5'1 and 125lbs. I have it on my non dominant hand but set to dominate so it's not picking up that many extra fake steps.

    Um...no. Just no. I have hypothyroidism and PCOS. No way I could burn that much at my size and age. I only take about 18,000 steps a day. I work on my feet all day and have a 1 year old son. So I'm lightly active plus a little exercise. I leave a 200 to 350 calorie "buffer" in addition to my 500 calores deficit that's built in.

    So far it's sort of working. I lost 3lbs in 3 weeks.

    I'm also from NJ....debatable if it's Central or South though....
    In the absence of medical issues, for your activity level that sounds about right. 18,000 steps a day is actually considered very active. The average step count for most people is far lower than that.

  • Jackson2348
    Jackson2348 Posts: 8 Member
    So I was curious about this and crunched some numbers. I have pretty accurate food logs. My FB burn for the past month (31 days) was 76,309. Eating and weight loss accounted for 75,534 (59,784 eaten+ (4.5x 3,500) lost). I used my trendweight rather than actual to account for fluctuations. So my Fitbit burn was 775 calories more than actual over 31 days. I can deal with a 1% margin of error, which is probably my error anyway. Also I have no thyroid, but am medicated appropriately.
  • KaleYogaGin
    KaleYogaGin Posts: 22 Member
    This has been a very helpful and interesting thread to read. Thanks guys!
This discussion has been closed.