Recommend an accurate bathroom scale

October 14, 2005 6:26 PM

I would like to buy a cost-effective bathroom scale that is pretty darn accurate for a 200 lb. guy -- margin of error plus or minus one pound. How do I buy one that is accurate? Any brand name suggestions? Do I have to buy one of those things with manually adjusted weights that run along a bar to get this level of accuracy? Please do not instruct me not to weigh myself more than once a week, etc. -- I am looking for a set of scales that will give me a reliable snapshot.
posted by Mr. Justice to health & fitness (18 comments total)

Just out of curiousity, what makes you think the plain old ones you could buy at the drugstore for 15 or 20 dollars aren't accurate?

Also, even if the scale lists you as a lb more or less than you would get if you found the world's greatest scale, it should still be a reliable measure, provided it's always in the same place and calibrated the same.
posted by duck at 6:48 PM on October 14, 2005

Just out of curiosity, what makes you think the plain old ones you could buy at the drugstore for 15 or 20 dollars aren't accurate?

Uh, maybe because he stood on them? The reading will often fluctuate 10 pounds or more depending on how you stand on them.
posted by delmoi at 6:52 PM on October 14, 2005

Mr Justice, my gym has a digital readout scale that is accurate to a tenth of a pound, but I don't know what it costs. It's worth the gym membership to me just to have access though.

BTW those 20 buck scales are crap. They can be off by twenty pounds without you knowing it. Seriously.
posted by konolia at 7:01 PM on October 14, 2005

Yeah, but your weight can vary by several pounds.
posted by caddis at 7:31 PM on October 14, 2005

that was supposed to include "over the course of a day."
posted by caddis at 7:31 PM on October 14, 2005

I use a Taylor digital scale that's accurate to within half a pound. I've tested it with a variety of hex dumbbells and it's spot on.

It cost about thirty dollars, so I don't know what konolia is talking about.
posted by Optimus Chyme at 7:32 PM on October 14, 2005

Oh but apparently the glass Taylor scales suck so don't get that one. :)
posted by Optimus Chyme at 7:37 PM on October 14, 2005

I don't know what your value definition is for cost-effective, but this scale certainly seems accurate. If 99.9905% accurate for $100 U.S. is suitably "cost-effective", you'll be pleased. If not, good luck.
posted by birdsquared at 8:08 PM on October 14, 2005

Asked, and answered, on Cool Tools.
posted by Ritchie at 8:24 PM on October 14, 2005

I have a sunbeam scale that I bought at the hardware store for $20 or so. It could not care less how I stand on it. I know it doesn't care how I stand on it, because, believe me, I've tried every conceivable way of standing, and nothing has worked yet. (And believe me, I'm super motivated to find the magic position, and I've had the scale for several years so if I haven't found it, it doesn't exist).

It did seem to vary a little if I put it on carpet or when I put it on uneven flooring in my old uneven-floored apartment. That's why I mentioned always using it in the same spot, which I do.

So as far as reliability goes, it's pretty clear the cheap sunbeam has no problems.

As for accuracy, my weight at the doctor's office is generally 3-5 lbs more than it is at home, which is exactly what I expect given that I weight myself nude and umm..empty... in the morning, and clothed and full at the doctor's office.

Why not go to target or such, pick up some weights from the fitness department and go test their scales for them?
posted by duck at 8:26 PM on October 14, 2005

I have an older version of one of these. The body fat measurement can vary depending on hydration and sweat or water on your feet, but the weight measurement is accurate to within .2 lbs. I wouldn't rely on the body fat % to tell you exactly how much fat you are carrying unless you are an average sized guy in average shape, but it is useful to track if your overall % is going up or down.
posted by hindmost at 11:35 PM on October 14, 2005

One of the nicer Tanita's... with a guest mode, ideally, because EVERYONE will want to try it out. Trust me. I weigh myself 2x daily and have lowered my weight/bodyfat from 215/25% to 165/12% it's good to keep you on track. Obviously how hydrated you are plays a role... which is where the nicer tanita's come in handy, they give you hydration readings as well. Perhaps not spot on with all the fancy info, but for trending... it's wonderful.
posted by mmdei at 2:02 AM on October 15, 2005

I bought a set of $100.00 digital scales a while ago, going with the theory that price = quality. It seems to have turned out pretty well in this case, the scales seem very accurate, far more than the previous scales I had which changed dramatically when you leaned in different directions.

Shell out the money and buy something you'll own and be happy with for decades.
posted by tomble at 5:00 AM on October 15, 2005

"accurate" can mean many different things, and it might be useful to consider in more detail what you need. there are at least four different definitions i can think of:

- stable - you put a weight on and the reading stays within some range while you look at the scale
- repeatable - you put the same weight on at different times and you get the same reading (with some error range)
- absolute value - you put a known weight on and get the correct answer (with some error range)
- precision - you get a readout to so many decimal places

for me, looking to monitor my weight (which is what i guess you might be doing too), the two important factors are stable and repeatable.

stable is tricky - if i move around on my scales, the value does change. but if i stand still and straight, it seems to be pretty stable. so i stand still and straight (no leaning over to one side to persuade it to say i'm lighter :o)

repeatability with simple mechanical scales (the cheap ones) is likely, in my opinion, to be pretty good, as long as you always use them in the same place, on a flat, hard floor, and check that the reading is set to zero before use (i check my weight every day, at the same time, in the same place, and it typically varies by about a pound, so my cheapo mechanical scales have a repeatability of about that - and i am amazed at some of the reports about people's weight fluctuating from day to day by amounts much more than that, but that's another issue...)

in particular, scales often have a printed warning about absolute accuracy - that they are only accurate to +/- 10 pounds, say. but for me that's not important. i measure my weight at the same time, in the same place, with the same scales, every day, and all that matters to me is the changes. i don't really care if i weight 140 or 200 - what i do care about is whether i have increased by 2 pounds. some scales with an accuracy of 10 pounds may, in practice, be repeatable to a pound or two.

now i don't know if that's the same for you. you might be needing absolute accuracy to compare with some medical requirements, for example. but it's at least worth mentioning, because repeatability tends to come at a much lower price than absolute accuracy, and for many uses repeatability is sufficient. and unfortunately, it's absolute accuracy that tends to be reported.

also, note that precision (eg konolia's comment above) alone doesn't necessarily imply anything else. you might find that one minute you weight 200.000 and the next, 221.543 (taking an extreme example). there's nothing to stop someone sticking a high precision display on scales with poor repeatability, or poor absolute accuracy.
posted by andrew cooke at 7:52 AM on October 15, 2005 [1 favorite]

Since you're going to be weighing yourself every day: As an alternative solution, you might consider buying a slightly unreliable scale, and then compensating for the unreliability as described in the Hacker's Diet here. Basically, since much of your day-to-day variation in weight typically comes from water weight anyway, the only way to get an accurate measurement of what you really weigh is to compute a floating average.
posted by gd779 at 9:05 AM on October 15, 2005

I second the Tanitas, at least the digital models. I got the Tanita 2202 Duo Scale Plus Bod for $37.99 from Amazon.com. I tested it and it was only off by 1/10th of a pound (I weighed a couple of 20 lb weights).

And it passes the "does it give the same weight twice" when weighing myself.
posted by exhilaration at 6:15 PM on October 15, 2005

My personal problem with cheap scales I've owned is that I can affect the weight by how I place my feet on the pad. It's probably repeatable if I always pick the same position but that just doesn't happen.
posted by smackfu at 10:02 PM on October 16, 2005

I have a Tanita model very similar to the one hindmost pointed out and love it (but it was much more expensive when I bought it).

For me, the problem is that I have size 14 feet. On cheaper scales, my feet hang over the edge and the just shifting my weight a little results in a 10 pound swing. On the one I own, the top is very solid plastic and the top half is a solid piece that doesn't flex and change the weight if I lean (and I've tried).
posted by aaronh at 6:25 AM on October 17, 2005