Scale Body Fat Accuracy

  • Anyone know how accurate the bodyfat reading on scales typically is?  Mine seems to swing up and down even when I know I'm losing fat.

  • From my research, scales that measure body fat can range from + or - 2 to 4%.  The important thing to remember, however you measure it, is to be consistent (how and when), and to view the percentage as progress.  if the percentage is decreasing, you should be good.  Do you measure it as the same time of day, each time you do it?  That could throw off your results.  Also, some body fat scales just aren't as accurate as others.

  • I do it right when I get out of bed before I go to the gym.  I weigh in once a week and this week I lost 3lbs and it said my BF% increased 2.2%.  I know it is wrong, (I can see my muscles getting bigger)  just wondering if other people are having the same problem with scales.  It was the best scale I could find at Walmart.  It's supposed to measure weight, BF%, and tell you how much water weight you have.  Just don't know how accurate it is to begin with.

  • The thing about Body Fat % scales is that how much water you have in your body makes the reading fluctuate.

    I recommend doing it in the morning, after you go to the bathroom (urinate).

    Also if you eat salty things, this will make you retain more water and can also affect the reading.  

    Also, if you are a woman, "that time of the month" will also affect the reading if you are retaining water.

    So basically what you can do is take an average, say over the course of week, taking into consideration the things I have mentioned above, and that will give you a weekly average and it is a better way to use the Body Fat scales (than just going on a single days reading).

    They use electrical impedance, which works off of how much resistance to the electric charge there is, that it sends throughout your body, water levels in your body can affect this greatly.

    Hope that helps.

  • You might want to look at various online calculators that use body measurements to estimate body fat percentage. They're not usually as accurate or consistent as calipers, but I think they do better than the scales, especially for consistency.

    Otherwise, LiveLoveLaugh's suggestion of averaging is a great idea. The more inaccurate your measuring device, the more frequently you'll want to use it so the errors average out.

  • This week the scale said I had gained 3.2lbs and my bodyfat went down 4.8%!!!  Not sure how I would have gained any weight at all since I've been eating the exact same foods and portions the entire challenge.  I'm not constipated or anything either.  I still have plenty of fat to lose too.  At least the BF% is showing it's going down I guess....  

  • Oh, and the workouts have been better and better each time.  Increasing weights on every exercise every time I go to the gym and faster pace on the cardio too.

  • So I really hope that mine is wrong...I have lost about 22 lbs. and my body fat has not changed on the scale by any percentage.  LOL.  I know I am gaining muscle and losing inches so my body fat HAS to have gone down...

  • My experience with scales and other electromagnetic version of body fat testing (ie handheld testers) is that they are incredibly inconsistent, and vary greatly with the amount of water in your body (as stated above).  A cheap set of calipers and a consistent form of measurement is the FAR more consistent and accurate.  You can grab them off ebay for a less than $15.  Read up on how to take accurate measurements.  Measure the same way every time.  You'll be much happier with what you see!  Good luck!


    I ordered this about ten days ago. Free shipping, no tax for us and it works great. Less than a big latte from Starbucks, and a whole lot more valuable!