T Nation

Tanita body fat monitor

Does anyone know the difference between the “Athlete” mode and the normal mode on the Tanita bf monitor? The difference can be anywhere from 5-10%!!! Surely there must be different levels of fitness and the two modes are pretty arbitrary? Cheers. Simon.

I begin to hate my tanita scale! First of all, it went from lbs. to kg., don’t ask me why!!! Then, it switched to another mode I don’t even comprehend! I put it on athlete mode, and stil I know my BF% is overrated by at least 2%. So now, I don’t know how much I weight because of that stupid mode switch, and I don’t have a clue of my BF, except I know it’s going down… Tanita NEVER replied the message I sent them.

Andre, I think the KG/LB setting is a small black switch on the bottom of your scale. Slide it to the other side and it should be back in LB mode. I have grown to hate my Tanita. 6 Weeks ago I was at 240 lbs and 17% bodyfat. Since then I have cleaned up my diet and I am now at 210 lbs but the scale tells me I am 21% bodyfat. I now have a legit 4-Pack that I didn’t have before so I know its wrong. All of this is done in Athlete Mode but sorry Simon I have no idea what the difference is.

I know - I use a Tanita (in athlete mode) and it’s BS. Usually about 3-4% higher than it should be. If your really dehydrated you’ll score worse. I called Tanita once before on this and they gave me a stroke job - I think I’ll call them again and raise hell as, just for once, I would like this thing to work correctly!

Cheers for the feedback bro’s. I suspected they were crock of shite, and I’ve never believed the readouts on them. I presume the handheld bioimpedance monitors are just as inaccurate?

My Tanita bodyfat monitor works great for me. The key is to use it at the same time every day. That is the only way you will get consistent readings. Even if it is wrong, if you use it at the same time every day, it will be accurately wrong every time. That way, you will know if you are gaining or losing body fat percentage.

I had mentioned in a previous thread that the reasons why some errors in measurement may occur… body hydration, coco puff crumbs covering the bottom of your feet or sweaty feet will give differing values, If it is measuring body weight incorrectly it will inevitably calculate BF% incorrectly as well… Most quality electronic manufacturer’s calibrate the operation of their equipment at about 23 Deg C. and a humidity level of less than 60%RH.
%RH less than 60% has little effect on the error, however for each degree of deviation from the calibration temp (assuming 23 Deg C)
there will be an induced error. There are many other areas that will induce error’s in measurement… power level (are these battery operated with fresh batteries?) If it’s line voltage is the frequency (50/60Hz) a factor? (Not likely).


Believe it or not, electronics are even affected by the varing gravitation effects of the moon on the earth. This is very minor and not really a concern for most consumer goods, but it gives you an idea of things that induce errors in measurement instumentation.
I work in a metrology lab as a calibration technician. I’ll try to contact the manufacturer and see if they will give me their calibration procedure…some Companies will…others want to make extra bucks by servicing and calibrating…I don’t own one of these scales so I would need info from them. If I can design a functional test that can be done at home and a method of adjustment, I’ll post it here.

Dale my man! You sure know your shit! I never realised there were so many variables, but I suppose it is a pretty comlex piece of kit really. It’d be great if you could find out about that calibration test and post it though. Cheers. Simon.

Thanks Simon
I was hoping someone at Biotest would see this post… I am available to calibrate equipment on site. This would enable your facility to make sure your measurement equipment is accurate. It’d be a shame to be putting too much Andro in the mix. I also design equipment test and calibration procedures… anything new to be added to the production line??? HeHe…
What the hell… worth a shot.

There are quite a few different models of scales and each has a specific method of calibration. What model do you have?
I have some info already, but need a chance to digest it. You’ll have to post a model #

Dale: Interesting stuff. Just for kicks, I have a Tanita TBF-551 scale. Look forward to hearing any ideas or information on calibration. -Epitome

Dale, I’ll have to get back to you on the model #. Cheers. Simon.

I have talked to their technical department and wasn’t sure which models to get specific info on, when I called again later to give them a couple of #'s just to get an idea, they were gone for the weekend. There are alot of models for home and professional use as well.
After reading some of the literature I can try to explain how accurate they are. By accuracy I mean how correct they are with respect to the exact value. It is not really a simple matter of stating they measure true body fat with a plus or minus error of a few %bf. I would need to go into a bit of Metrology101 to give a clearer picture of how accurate/inaccurate they are… The biotest team involved in clinical trials would undouted use some of these principals. I will explain it if there is interest, but it would waste space on here otherwise.

Dale, my Tanita is a model tbf 531. Any extra info is always appreciated - ever keen to learn!!! Thanks. Simon.

I’ve had loads of problems with my Tanita, and considering how expensive they are I would expect better. I’ve found they are just too sensitive. I’m going to get a pair of calipers soon, so I’ll have a comparison.