Charge 2 calorie counter accuracy

[K_wallace]

Hey guys,

I'm new to exercising regularly. I'm trying to lose weight (5'1" 185 lbs) to become healthier and feel better. I've been working out and watching my diet for about 4 weeks and my boyfriend got me a fitbit charge 2 this weekend to encourage me to keep going. Well, my question is the accuracy of the calories burned on my Fitbit. I had been using a treadmill to track my progress, but today I noticed that my Fitbit had recorded my calories burned as 195 more calories than what the gym treadmill was reading! Can someone please tell me if this is accurate or if I'm doing something wrong?

[USAF-Larry]

@K_wallace, the calorie burn on your Charge 2 will be a lot more accurate than the treadmill. It won't be 100% accurate, but it will be a lot more accurate.  The Treadmill uses an "average" calorie burn based on the speed, incline, and time.  The Charge 2 uses your profile information for age, height, weight, and sex, plus the heart rate during exercise to calculate calorie burn.

[GershonSurge · Accepted solution]

Many of us have found the wrist devices overestimate calories by 10-15%. Less for those who are sedentary.

[Frog55]

My calorie count on my charge 2 is ridiculously off. I just did a 15 min 1 mile walk.  It says I burnt 694 calories. That can't even be close. It shows me burning 1800+ calories a day. With intake if around 2000 calories daily,  I should weigh 100 lbs. This is my 3rd one, all do the same thing. I've unpaired old ones,  uninstalled and reinstalled my app, I give up. I've tried to get answers on if my app has wrong settings,  if my device has wrong settings, just can't get a straight answer. After 3 fitbit charge 2 in 4 months, I'm thinking the problem is somewhere on my side, but can't get any answers. Is it my android phone, as most comnents I've seen have iPhone . 

[SunsetRunner]

My Charge 2 seems fairly accurate to me- today it says I've burned about 2900 calories In total  (it's 7.30pm). This sounds excessive but I've been up since 5.50am, done a Spin class, Fat burn class, and stretch session in the gym (30 mins each), been for roughly 90 minutes of brisk walks, and been on my feet for the whole day until 5pm, apart from at lunchtime.. so for me (21 year old female, 8st10 and 1.69m), that seems about right? So I'd say the Charge 2 itself is quite accurate!

[Frog55]

My frustration is coming because it is saying I'm burning 1800+ calories a week, and I sit at a desk for 7 hours a day. I can leave it on my nightstand and it says I'm burning 600 calories, while not even on my wrist! I'm thinking I have some kind of setting wrong, but just can't figure it out. Your activity level is amazing! I don't expect perfection, just seems it's way out of whack. Maybe I'm wrong,  who knows


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[wcdean]

It records your Resting Metabolic Rate as calories burned if it isn't on your wrist, which would also answer your question on burning 1800 calories a day at a sedentary job. Presumably your RMR is around that. 

It tells me my RMR is 1732. I had my official RMR calculated using gas spectrum analysis on my carbon no oxide output. Basically you breath through a tube for 25 minutes or so with your nose plugged. So with regards to RMR their algorithm is fairly precise.

That said I agree that my daily caloric burn seems to be much higher than to be expected and I do a lot of physical activity. I wonder if things such as body type/composition also cause variance. 

EDIT - I reread the original post and it days 1800/week? I am not sure if you mean 1800/day or perhaps 18000/week? If the latter than perhaps your RMR is around 2500/day. Depends on a lot of factors. 

[Frog55]

Yes, it's starting to make sense to me. I think I'm trying to be too precise with it. I really didn't realize a person burns calories while sleeping. I just assumed one had to be doing physical activity to burn calories. I learned something thus week, who knew? 😊


Sent via the Samsung Galaxy S7, an AT&T 4G LTE smartphone

[Jrly]

i am having the same problem, just got my fitbit yesterday. I've been awake for one hour today and already it says i've burned 292 calories. I literally have only walked from the bedroom to the recliner then to the bathroom once and back to the recliner. yesterday in just 5 hours it said I burned 1,555 calories. That cannot be right because it rained all day and I did no other exercise besides normal everyday walking in the house. Trying to figure out if there's a setting on the app that I am missing. Very frustrating.

[DeafFred]

Even when you're doing nothing except for sitting around or sleeping, you are using calories.  Your body uses a certain amount of energy just to keep you breathing, to keep the blood pumping (remember your heart is a muscle that is working continuously), to digest food, to keep the brain functioning.  Take a look at this snapshot of my activity from this morning:Lazy Sunday morning 🙂

 You can see that right from midnight, my fitbit tagged me as using energy - about 6 kcal per time click (can't remember the interval at the moment).  You can see where I got up and did a little cleaning then around 11:00am sat down at the computer to answer some emails.

The only time you're not using any energy is when you're dead.

[Frog55]

I have figured out that I was stuck in the weight loss formula from the past of exercise/physical activity = calories burned= weight loss, providing we are eating healthy.  This is still true, but I did not realize the body is burning calories all of the time, and the tracker is picking up even those calories burned.  I did adjust my stride by measuring it myself instead of automatic which helped my step count be more accurate. (It was picking up arm movement as steps - I sit at a desk, but lots of arm movement)  I had to change my mindset a little, as it was making me crazy! If any of my explanation is not correct in regards to calories burned, please feel free to correct me! I've gotten great responses to this question. 


Sent via the Samsung Galaxy S7, an AT&T 4G LTE smartphone

[IgnacioO]

As people have pointed out already, there is something called Basal Metabolic Rate (or BMR link to Wiki if you really want to learn more about it), which is calculated on your sex, weight and height and is the average calories you burn just for existing (Calculator), no walking, no standing, no opening eyes, not moving arms, nothing but breathing and existing.

For me that is 1910 and it means that every 15 minutes (Which is the unit in which the fitbit tracks time for me at least) just for sleeping I'm burning almost 20 calories, or 79,5 an hour.

On summertime I do lot's of rollerblading, at least an hour a day for at least 4 days a week (To also have into account good leg muscles). Let's say that now I'm walking to work -late as usual- on a hurry which raises my HR from the resting 60 to between 90-110 and suddenly my calories burnt for that time instead of 20 are 60-70. This means I'm almost tripling my BMR for that short period of time, so up from 1910 I'm closing in on 1960 just for a 15 minute walk, or 2110 for just an hour of walk a day. Without considering all of the other activities I have to do in the day.

Another example, is me sitting at work, just for sitting in front of a computer for 15 minutes gets my calories from 20 to 27.

All of this, is to recommend you analyze all the data you have at hand and try to figure it out yourself, it might be a bit over the average for fit people but I've found a lot of logic on the counting.

[ScottMcCathon]

This is due to your metabolism you will burn calories no matter what you're doing as long as you're alive. Your metabolism is basically how many calories you burn if you laid in bed all day and did absolutely nothing. Metabolism is just energy burned to live, keeping your heart pumping, breathing, digesting, etc.

[Frog55]

Yes, I knew that part. Got everything figured out. Thanks 

Sent via the Samsung Galaxy S7, an AT&T 4G LTE smartphone

[Wildcreek]

My calorie count during exercise is way off.  I wore both my Polar and Fitbit to test it.  Are you saying if I adjust my stats, I can get a more accurate calorie count?  What should I adjust

[Rich_Laue]

@Frog55 adjusting the stride will never affect the steps counted, however it will make tye reported distance more accurate durring walks.

As for losing weight the formula is really very easy, be more active, eat healthy and eat less.  This will not say how fast you will lose weight, but the weight will come off. Many however first  notice the change in lose fitting clothing before the scale moves. This is still good in that the fat is being lost and muscles are being built.

[Wildcreek]

It appears my question was not understood as it was not answered. I have a fitbit charge 2.
When I exercise, it does not accurately record the calories burned. It was quite a bit under. I know this be3cause
I tested it against my Polar exercise watch which I have used for years and know is accurate. I understand,
fitbit figures calories calculations by the personal data entered about the user, ie, weight, age, height, etc.
How do I adjust the fitbit to increase calorie recordings to be in alighnmnet with my Polar? That is, how do I increase
calories burned? Do I put in a younger age? Will that increase calories burned?
Wildcreek

[GershonSurge]

We can answer the question better if you explain how you know your Polar is accurate.

[Wildcreek]

I have used my Polar for 10 years. My calories count with my Polar is similar to others in my classes.
The Charge 2 is less than others in class and I know my body and exercise ability.
I put both my Polar and fitbit on my wrist, and they are off quite a bit. About 150 calories in one hour.
So, I know it is off because I can compare it to others in class with similar abilities and it is way off from
my Polar when worn at the same time.

Linda

[SunsetRunner]

Good answer.  I've noticed mine overestimates burn by about 35-45%.  A reasonable fix was simply to decrease bodyweight by that amount.  Not perfect but very close.