Hmmm, you estimates may be a little low. Not sure of your stats, but my BMR (mifflin the formula MFP and Fitbit use) is about 1270. If I am active i.e. 10,000 steps a day I can easily burn about 2000 calories. Someone with a BMR of 1800 should be able to burn considerably more for similar activity. or a 15k-20k step day I might burn 2,300 (this is very difficult for me though), again you should burn considerably more with an 1800 calorie BMR. If sedentary, I would usually burn 1400-1500.

Don't look at general walking calculators for your total calorie burn. I think these may be fine for dedicated walking, but not steps accumulated from general or non-step activity. With my stats, I can burn 95 calories an hour walking 4 mph, Fitbit credited me with 95, my heart rate monitor/GPs app with 91, an online calculator that is said to be accurate with 93. These are all pretty close to each other. So I really doubt that you would burn 75 calories per mile. The standard rule of thumb a lot of running magazines use is 100 calories per mile--but they don't seem to specify individual stats when it is generally accepted that larger, more muscular and heavier people burn more for the same activity than lighter, smaller or less muscular people. I don't know your specifics and am poor with the metric system--but at your height (I am 10 inches shorter) and gender I would expect you to burn ore than I if you were also walking 4 mph. Males always have high sounding calorie burns to me so I can't comment on the specific numbers.

But I will say, your fitbit calorie burn is not based on your steps exactly. So doing a steps to miles calculation won't work perfectly. The fitbit calorie burn and the steps are calculated by fitbit from the movement data. It has a tri-axis accelerometer that tracks movement forward and back, up and down and side to side. It translates that movement into steps--but I know it picks up some movement that isn't rated as a "step" (It is a little different than how an old-school pedometer works). The calorie burn is a portion of your Mifflin BMR each minute plus whatever it credits you for activity. The calorie burn is more how much and how fast you move each minute (only if it is movement your device can pick up where it is worn). Or how much and how fast the movement your device can sense each minute--I mention because sometimes people get inflated calorie burns driving bumpy routes, riding motorcycles or golf carts, etc and sometimes if they wear it in a different way then recommended (like wearing a one/zip on a wrist or shoe when it is calibrated to be worn on the torso). The crazy thing with unusual placement is sometimes the step count will be fine but the calorie burn will be higher (because the calorie burn isn't really just about step count, I notice impact and up and down movements does effect it).

10,000 steps for me is less than 5 miles as well. It may even be similar (a little less) to yours which is odd since I am 5' 1". It does depend whether fitbit credited me with walking or running though. But the estimated distance isn't what fitbit is using to estimate calorie burn. Having your stride length correct does help keep your fitbit distance more accurate and it makes it easier to compare your fitbit calorie burn for walking and running to other sources (since other sources use distance and speed).

I think it is helpful to have another basis of comparison for seeing if your fitbit calorie burn seems realistic. I personally don't find mine to overestimate in general, if anything it underestimates my non-step or resistance activities. It does credit slightly more than my heart rate monitor for moderate and slower walking, but it seems pretty inline with what a lot of of line calculators estimate. From my results, wearing my fitbit and logging my hrm calorie burn for non-step exercise seems to put me within 72 calories a day of accurate compared to my results. I do wear a fitbit one clipped on either my bra or waistband--it may be different for different devices worn differently.

Anyway, I think a TDEE calculator would give you a better basis of comparison than converting your steps to miles and adding on a walking calorie burn for that mileage. Step count can give you a clue where your activity level lies--assuming you don't do a lot of non-step or resistance activity (though hopefully you do at least some as strength training is very beneficial as are other non-step activities). I find if I get 10,000 steps and have exercised an hour--my calorie burn tends to be close to what many TDEE calculators estimate as "moderately active". It does depend a bit on the exercise though, since if I logged non-step exercise and most of my steps were from general activity or walking my calorie burn tends to be higher than if the 10,000 steps is inclusive of my exercise calorie burn. (Which makes sense as 10,000 steps from general activity plus a one hour swimming or weight lifting workout is more accumulated activity than a 10,000 step day where 5,000 came from jogging or zumba class).

MFP actually kind of has a TDEE calculator, but it is a "pre-exercise TDEE". I think it is a useful awareness exercise to run your MFP plan at all four activity levels and note the "calories burned from daily activity" for each. This can take a few minutes, then you can set it at whatever level you want when you finish. It will give a range of what someone with your stats might burn if sedentary, lightly active, active or very active. There are only four options, when individual activity varies more. And MFP intends it to be your "calories burn from general activity" (found in your MFP goals page and is intended to estimate what you might burn at that level excluding exercise) if you choose the right level so it may give a lower calorie burn than other TDEE calculators and lower than when you add in the exercise. What activity level are you set for? With your step count I would guess you to be between Active and Very active (the 14k steps is more like very active). So if you are set for sedentary you will no doubt see large fitbit adjustments. MFP uses the "calories burned from daily activity" as the basis of comparison when it calculates your fitbit adjustment.

If you use another TDEE calculator (Scooby is a popular one), be sure and run it with the stats entered on your fitbit account and the "Mifflin" bmr formula (it is closest to what Fitbit and MFP use). If you run it with Harris-Bennedict you will see a higher calorie burn estimate though. And if you run it with Katch-McCurdle (spelling? the one that uses lean mass rather than age and gender), it can go either way depending how muscular you are for someone of your height and weight.

Doesn't matter what you calc RMR to be, but rather what is Fitbit using for your BMR? (which is lower than RMR by 150-250 cal/day)

Look at your Activity chart with calories burned in 5 min, the non-moving time day and night stand out as the lows.

That calorie burn / 5 x 1440 = BMR they are using.

As Kim mentioned, usually pretty close to the MFP Mifflin BMR. How does yours compare?

Then look for steps during the day where you know full well you didn't take steps, obvious errors in reading motion.

At least you got measured stride length, that helps along with mass for Fitbit to know how full were the strides based on accelerometer data.

You may be walking in such a way as to make it think you were taking bigger strides then your manual settings - so more distance in same time is faster pace is greater calorie burn.

Well, it looks like it's overestimating.

Maintained weight the week before last, eating all Fitbit exercise calories and at a supposed 500kcal/day deficit.
Lost 0.3kg over the last 6 days with a (supposed) deficit of 750kcal/day.

I guess I can work around it - 0.3kg/week is fine with me - but is there anything I can do to improve the accuracy of the calorie calculations?

Or does it sound like a faulty unit? (although step counts are accurate - it's more the step>kcal that seems off)

Only way would be a walking and/or jogging test to confirm faulty unit.

If you can make activity of a workout (my Zip you cannot) so you have stats for just that block of time, then walk known time and distance at specific pace like 3.5 mph good the whole time, and see what calorie count is. Flat is better. 20 min would be good test, too short might not point out variations.
Now do a jog up to 6.3 mph the same way.

Then compare to the Gross figure here, which is what Fitbit, HRM, treadmill, database, ect, would be reporting.
http://www.exrx.net/Calculators/WalkRunMETs.html

That doesn't look good at all.

Variance walking not that bad, still 8% inflated.

Do that for steps all day long, that's decent overage.

But the running - wow. I usually found flat runs to be decent estimate, with 10% underestimated. But like you, since I usually have hills and such, manual logging.
But that is really off.

I'm not sure what proof Fitbit would need to agree that something sounds really off. Though they should be able to have someone analyze the data.
I saw a hack that allowed looking at the raw Fitbit data, and you could see impact data and such, it's the Fitbit servers that do the math to finely tune the results. The unit itself just has default stride length and uses that until sync.
After sync you could have your distance and calories change on unit as it's adjusted I suppose.
Seems like someone could view that and decide that indeed, for your logged mass and stride length, and times you were walking - that's way off.

But it's still hard to base it on steps, I would not use steps. Distance and time is what counts.
A shorter legged person same mass doing same pace and time would burn the same as you with longer legs.
And since steps vary so much, just can't divide it down to steps. Well, accept the stride length of course that much is based on.

I have a Charge HR and fitbit uses the HR data to help calcuate calroies burned. Its a shame that the fitbit HR technology is absolutely crap and does not reflect my heartrate at all. at rest it is 10-15bpm higher than my hr and this contiues and gets worse at higher hr. this in turn completely screws up the calories calulation.

davert123 wrote: »

I have a Charge HR and fitbit uses the HR data to help calcuate calroies burned. Its a shame that the fitbit HR technology is absolutely crap and does not reflect my heartrate at all. at rest it is 10-15bpm higher than my hr and this contiues and gets worse at higher hr. this in turn completely screws up the calories calulation.

Yep, others have reported the HRM doesn't work well for them. Yours is first comment about lower end being inflated. Usually some will comment it's fine until it goes high, then it either blanks out or doesn't go as high as chest strap reports.

And since HR is basis for calorie burn during exercise - if you do enough of it and/or intense enough - it could be badly estimated.

Daily activity though is not HR based.

Of course - I'm guessing many got the HR-based device for more than just weight loss, and want the HRM to be accurate for other reasons, like training methods.
Why else get it?