How does the Aria 2 measure body fat percentage?

[Kieran9619]

Hi, 

First things first, I'm a lover of my Fitbit charge 2, and I believe the aria 2 would be ideal for compatibility of measurements. However, I'm a sports scientist and also a personal trainer and I believe that the scales are to some extent overpriced, believing the weight to be accurate, BMI figure should be obvlivious for 95% of the population due to it's inaccuracy of measurements it take into account. But my question really is If anyone can answer, how does it measure your body fat percentage? And how accurate can that be? Because a bioelectrical impedance analysis cost cheaper and has a more detailed and structured procedure. I understand Fitbit wants to be the Apple IPhone market for sport, however the description doesn't provide significant enough detail for me to buy this for it's cost. Someone please help.

Moderator edit: updated subject for clarity

[JuanJoFitbit]

@Kmilacesar Thank you for getting back! The advice that shared my friend @Baltoscott is very helpful. Please try it out. If you see that the issue persists, let us know and we'll be happy to follow up.

[Torgerson]

Same.  My bf% has gone down (from 44% to 39%) over the last six months, per the scale, but my BMI is normal, I go to the gym every day, and I am 36 years old. I am pretty confident that half of my body weight is not fat. Very frustrating. The scale was a total waste of money.

[LZeeW]

@Torgerson   Have you tried the suggestion of putting your scale in lean mode? 

[Baltoscott]

@Torgerson - how does your Aria 2 compare to other estimates of your body fat % such as this on-line calculator which is based on tape measurements of several parts of your body?

For me, the BF % is 3-4% higher on the Aria than the on-line calculator.  Both obviously are estimates, but the difference is not all that much.  The main reason for a BF scale is to easily measure your trend (i.e, I like to think that the tape measure estimate is more accurate, but I’m not going to do it daily like I do with the scale).  In any event, a 5% drop over six months sound great and seems to validate your hard work at the gym.

[JuanJoFitbit]

@Torgerson Thank you for joining this thread! I'm sorry to hear that your Aria 2 is not providing body fat percentage accurately. The tips that shared my friends @LZeeW and @Baltoscott is correct and helpful.

Please check out this post in order to know how to change to "Lean mode". After this, restart and re-calibrate your Aria 2 by taking out the batteries for 15 seconds and put them back in. After this, weigh yourself 5 times in a row and see if the issue gets fixed.

Let us know how it goes! 

[RCherie]

Good to know! Thanks 

[ekispecki]

my aria 2 scales seem wildly inaccurate. It is consistently putting my BF at ~37%. Have tried resetting and recalibrating and switching to new batteries and also changing to lean mode. Using the online body measurement calculators my BF is closer to 23-26%

[LZeeW]

Hello @ekispecki and welcome to the forums.  I had a similar experience when I set up my scale.  I used online calculators and compared myself to some of the pictures that show people with known percent body fat.  I switched to the lean mode, but it took four to five days of weighing myself to settle down to a more reasonable number.

[CBM34481]

Why does my Aria 2 scale measure my body fat differently based on my gender profile (male vs female)? When male was selected my body fat measured 16.8, when female was selected my body fat measured 27.4. If the scale measures biometric impedance shouldn’t this number be the same regardless of gender selection?