Fitbit overestimating my calories burned?

I don't have a Fitbit but most exercise gadgets and equipment tend to overestimate calories burned. The elliptical at my current gym reads 300 calories burn for 30 minutes of exercise. The one at my previous employer read 250. The treadmill at the gym reads almost 200 calories burned for 30 minutes. My treadmill at home reads 150. I would go with the most conservative number.

I don't have a Fitbit but most exercise gadgets and equipment tend to overestimate calories burned. The elliptical at my current gym reads 300 calories burn for 30 minutes of exercise. The one at my previous employer read 250. The treadmill at the gym reads almost 200 calories burned for 30 minutes. My treadmill at home reads 150. I would go with the most conservative number.

why not go with the "correct" number?

I don't have a Fitbit but most exercise gadgets and equipment tend to overestimate calories burned. The elliptical at my current gym reads 300 calories burn for 30 minutes of exercise. The one at my previous employer read 250. The treadmill at the gym reads almost 200 calories burned for 30 minutes. My treadmill at home reads 150. I would go with the most conservative number.

why not go with the "correct" number?

Taht is the question...how to know the "Correct" number.

I would also go with the lower of the numbers just like if I find varying amounts of calories listed for the same product I go with the higher one.


I dont know if it is something they do on purpose, but it seems like most do overestimate....maybe to make the person feel better?

no, they don't overestimate to make you "feel better". My point was that they are all estimates largely based on the info you put into it. If you just hop onto a machine without setting it up, its probably going to give you crappy numbers. If you set up the machine and use the HRM, it is going to give you better numbers (but still estimated). Then, you have to understand the number it is giving you - is it the additional energy your burned by doing the exercise or is it the total energy burned during that period.

Comparing various machines is also very difficult to do in a meaningful way. The resistance, incline, movement mechanics, etc are all different, so unless you are able to measure resistance, you can't compare. Just because you set it to level "10" doesn't mean level 10 is the same resistance on each machine.

All variables - all up to you to set it up and understand. As far as how the estimates are calculated, they are pretty much all based off of a limited number of statistical models that all correlate fairly well with each other - in other words, if you are comparing apples to apples, they are all close. Each treadmill manufacturer doesn't take the time or effort to develop their own models.

I've been using my new Fitbit One for a week, and it seems like it's been overestimating the amount of calories I burn. For example, today I went for a run and used the Fitbit activity timer to see how much calories I had burned just during the workout. I also used RunDouble, since I'm doing C25k (end of Week 7), though I have RunDouble set not to synch with MFP anymore. At the end of the run, RunDouble told me that I had burned 250 calories. Fitbit, though, said that I burned 370 calories during that period. Which one is more accurate? It seems like the Fitbit would be, but these numbers seem so insanely high. Has anyone experienced this?

Though I am currently fitbit-less, I am a huge advocate! I have owned (and lost () four of the devices and had them all sync with MFP. Are you wearing your fitbit as prescribed? The One is extremely accurate, more accurate by far than the Flex or Force as it is attached to your torso and can't be tricked by things like swifter movements with your arms.

Do you have your MFP account set up so Fitbit can adjust calories up AND down? You have to go through settings and allow the down modification, though the up modification is automatic when you set Fitbit up initially. I find this to be the most accurate way to use the device to measure calories. That way, if Endomondo records that I burned 500 calories doing 45 mins on the step mill, but my fitbit noticed that my body really wasn't moving all that quickly, it can adjust that 500 calories down to the 300 that I really burned.

Regardless, nothing is going to be 100% accurate. Definitely knock off a few hundred calories when you are eating back anything you burned just to be sure, but know that of all of the devices and programs out there (save the Bodybug which is hideous), the Fitbit is going to be the most accurate.

It has been accurate for me. Before I fell off the wagon, I lost exactly what what I was suppose to based on calories eaten and fitbit adjustments. This is over a few months so it all averaged out. Day to day accuracy- who knows but over time, it was great for me. I using it again now to help keep count.

My Fitbit has also been very accurate for me, & I eat back every single one of the exercise calories it gives me, everyday. I also have the Flex, which people often worry overestimates, but I haven't had that problem.

I would just go with what it's telling you for a month or so, & keep track of your weight as you go. You won't know if it's accurate for you if you don't let it do what it's supposed to do.

I know this is an old thread, but I just ran across this because I was searching for the same question, and thought I would throw in my little bit of data for the benefit of future searchers:

I have been running 3.1 miles (5k) with RunDouble. I run at about 12'15"/mile, and it says about 480 calories for the 38 minute run. I have repeated this same run many times over the past weeks, with very similar numbers. And RunDouble DOES have my age, height, sex, and weight (actually, it thinks I'm about 5 pounds heavier than I really am because I haven't updated it in a couple weeks)

I just got a FitBit Surge yesterday and did this same run. 3.1 miles, at 12'01"/mile. FitBit gave me 672 calories for the 37 minute run. FitBit also has my age, height, sex, and weight (and it has the CORRECT weight because I use a FitBit Aria scale).

This is a difference of almost 200 calories in under 40 minutes. I certainly WISH my BMR was that high! Actually, based on FitBit's numbers, my BMR for that period should have been about 45 calories. So, if FitBit and RunDouble are using the same algorithms, where did the other 150 calories come from??? Both devices are using GPS to track the distance, so stride length shouldn't come into play. The FitBit does know a few things that RunDouble doesn't . . . it knows my heart rate, it knows my number of steps (and therefore cadence), and it knows that I had an elevation gain of 30 feet over the run. Could it be that these variables were taken into account and accounted for an additional 25% more calories? I doubt it.

I don't know which of these numbers is correct. Based on my weight loss results so far, I have been suspicious that RunDouble was underestimating. Now I'll start tracking my results against FitBit's numbers and see what I come up with. However, based on these numbers, I do not think the only difference between RunDouble and FitBit is BMR; the difference is too high for that.

DaveAkeman wrote: »

I know this is an old thread, but I just ran across this because I was searching for the same question, and thought I would throw in my little bit of data for the benefit of future searchers:

I have been running 3.1 miles (5k) with RunDouble. I run at about 12'15"/mile, and it says about 480 calories for the 38 minute run. I have repeated this same run many times over the past weeks, with very similar numbers. And RunDouble DOES have my age, height, sex, and weight (actually, it thinks I'm about 5 pounds heavier than I really am because I haven't updated it in a couple weeks)

I just got a FitBit Surge yesterday and did this same run. 3.1 miles, at 12'01"/mile. FitBit gave me 672 calories for the 37 minute run. FitBit also has my age, height, sex, and weight (and it has the CORRECT weight because I use a FitBit Aria scale).

This is a difference of almost 200 calories in under 40 minutes. I certainly WISH my BMR was that high! Actually, based on FitBit's numbers, my BMR for that period should have been about 45 calories. So, if FitBit and RunDouble are using the same algorithms, where did the other 150 calories come from??? Both devices are using GPS to track the distance, so stride length shouldn't come into play. The FitBit does know a few things that RunDouble doesn't . . . it knows my heart rate, it knows my number of steps (and therefore cadence), and it knows that I had an elevation gain of 30 feet over the run. Could it be that these variables were taken into account and accounted for an additional 25% more calories? I doubt it.

I don't know which of these numbers is correct. Based on my weight loss results so far, I have been suspicious that RunDouble was underestimating. Now I'll start tracking my results against FitBit's numbers and see what I come up with. However, based on these numbers, I do not think the only difference between RunDouble and FitBit is BMR; the difference is too high for that.

Another thing to consider is, what is your activity level set to on your Fitbit? If you are set to sedentary, you will see bigger numbers posted than if you are set to lightly active or active. I've found that Fitbit assumes about 3000 steps per day for sedentary and will start upping your calories burned after this amount. A 3 mile run alone will put at about 6000, and then when you add your normal activity you are going to see bigger adjustments. It doesn't necessarily mean they think you burned X amount in that one activity, but that your TDEE for that day has increased by X amount over what they thought it would be.

Also, it can depend on where you are at for your activity level in the day. On Sunday, in the afternoon, I walked 3 miles. After walking 3 miles, I had an almost 500 calorie Fitbit adjustment for the day because of how many steps I was above my set activity level. I didn't necessarily burn this many during this walk alone, that's just where I was at based on it's expected values. Monday morning, I walked 5 miles first thing in the morning. My Fitbit adjustment first thing in the morning was also about 500 calories. This is because, prior to my walk, my activity level was lower than expected, so I was actually playing catch up. By the end of the day, after my normal activity came through, I ended up with a much higher overall adjustment for the day.

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SezxyStef wrote: »

@DaveAkeman I have a jawbone but they are similar...

My calories in are tracked here using a food scale and my calories out are tracked with my Jawbone.

I've been watching my monthly totals and this is what I Have so far...

April Calories burned = 59798
April Calories consumed = 56815

Difference is 2983...I lost 1lb in april.

May Calories burned = 66821
May Calories consumed = 58502

Variance = 8319 - I lost 2 lbs in may...

Still waiting on June to finish but so far

June burned = 36492
June consumed = 32820

Variance = 3672...no loss yet but suppose to weigh tomorrow.

Wow . . . that is INCREDIBLY consistent with your weight. I'm actually very, very impressed! Thank you for sharing!!!

DaveAkeman wrote: »

SezxyStef wrote: »

@DaveAkeman I have a jawbone but they are similar...

My calories in are tracked here using a food scale and my calories out are tracked with my Jawbone.

I've been watching my monthly totals and this is what I Have so far...

April Calories burned = 59798
April Calories consumed = 56815

Difference is 2983...I lost 1lb in april.

May Calories burned = 66821
May Calories consumed = 58502

Variance = 8319 - I lost 2 lbs in may...

Still waiting on June to finish but so far

June burned = 36492
June consumed = 32820

Variance = 3672...no loss yet but suppose to weigh tomorrow.

Wow . . . that is INCREDIBLY consistent with your weight. I'm actually very, very impressed! Thank you for sharing!!!

@DaveAkeman I was too actually when I was checking it out. This includes daily movement, weight lifting (small calorie amounts given) plus any purposeful exercise I do like walking, running etc.

It will be interesting to see how it stacks up in the coming months.

If you were sure that the device was accurately measuring your HR during exercise I would go with those numbers but my sister has a Charge HR and finds that it is really inconsistent with monitoring her HR during exercise that pushes her HR above 120. She has checked it against her Polar HRM and the Charge is usually either way over or way under with the HR reading.

I use a Flex and find it good for walking and daily activities (as it is designed for) but I prefer to use my Polar for aerobic stuff like running and then manually log that.

Experimenting over time is probably the only way to tell how it works for you.

I usually get 103-105 steps every time i do a manual count of 100 steps.
I have fiddled with my stride length, but it hasn't made any difference!

charlieandcarol wrote: »

If you were sure that the device was accurately measuring your HR during exercise I would go with those numbers but my sister has a Charge HR and finds that it is really inconsistent with monitoring her HR during exercise that pushes her HR above 120. She has checked it against her Polar HRM and the Charge is usually either way over or way under with the HR reading.

I use a Flex and find it good for walking and daily activities (as it is designed for) but I prefer to use my Polar for aerobic stuff like running and then manually log that.

Please note that I am NOT saying that the Charge HR is accurately measuring either your heart rate OR your steps!

In actual fact the Charge HR is extremely slow to respond to changes in heart rate (up or down) compared to other wrist worn HRM devices (such as the Mio line and/or the Schorsche Rhythm+), and it often "tilts" when you get sweaty, or your HR goes high. Or low. Or you move your wrist a lot.

And I am actually saying that if you walk fast (think 110 to 130 steps a minute), the Charge HR misses a LOT of steps. And if you chop vegetables, or brush your teeth, it adds a whack of them.

Nevertheless, maybe because as Heybales said in the Fitbit group, exercise is only a small part of the day? maybe because my (obvious to me) muscular adaptation to walking is counteracted by the missed steps? or because I walk up and down hills and the Fitbit doesn't really know that? Or because on average I walk well over 15K steps a day so what's a few less or a few more? be that as it may, the TDEE estimate given out by my Fitbit seems to be acceptably accurate for me, and it allows me to eat quite a few delicious extra calories in relative confidence

I am far from a Fitbit evangelist: I think the Mio HRM is way more accurate, I think that Fitbit should be ashamed at the crappy comfort level their strap and fastening mechanism provides. And they should be ashamed of the games they are playing when it comes to (in my opinion deliberately) making their phone app not able to capture GPS tracking during activity recording so as to encourage people to buy a Surge.

yet, I would still replace mine right away if I were to lose it.