two scales say different weights  what one is right?
trulyhealy
Posts: 242 Member
the scale i’ve been using for a month and a half is a scale i can only get to once a week and isn’t the most practical because at the start i didn’t have my own scale.
i then bought my own and one day in the morning i weight myself on each one after another.
for backgrounf info my start weight was about 11 stone 11 pounds (165 pounds)
one morning i weight myself on each scale one after another and the scale i’ve been using all along said my weight was 11 stone 6 pounds but the new scale said i was 11 stone 11.
what one is right? what if i’m bigger than i thought? using my own scale would be easier but i don’t know if it’s right. it’s a £15 weight watchers scale.
i then bought my own and one day in the morning i weight myself on each one after another.
for backgrounf info my start weight was about 11 stone 11 pounds (165 pounds)
one morning i weight myself on each scale one after another and the scale i’ve been using all along said my weight was 11 stone 6 pounds but the new scale said i was 11 stone 11.
what one is right? what if i’m bigger than i thought? using my own scale would be easier but i don’t know if it’s right. it’s a £15 weight watchers scale.
0
Replies

The answer is both. Scales vary, unless they're scientifically calibrated. Worry less about the number, and concentrate on the trend, and for goal weight how you look and feel. So long as you're heading down on average (weight fluctuates naturally, especially for women), you're fine. I know it kind of sucks, but it's largely psychological. You've still lost 5 lbs, and that's great!16

Just place the 2 scales one meter apart. Place one foot one one scale, the other foot on the other scale, and exhale deeply. If the readings don't match, your diet is unbalanced .16

No matter what the scale says, you're the same size on each one. You don't get bigger from being on a different scale. :flowerforyou:
Regular home and shop/gym scales are a little bit imprecise, so they'll often differ a little bit even if you try one seconds after the other, wearing the same clothes. It's the scales, not your body.
If it's been minutes to hours in between using the two scales, your weight can actually have changed a little bit (drank some water, sweated some out, ate something, used the bathroom, slight difference in clothing, that sort of thing  even exhaling changes our weight a teensy tiny bit).
I know it feels frustrating, but truly, it doesn't matter. Just stick to using your new scale, and watch how your weight behaves over a period of several weeks. If you're on target with your weight loss, it may fluctuate up and down a bit along the way, but the overall trend will be downward.
The absolute number that appears is kind of meaningless  think about it, some of us weigh in pounds, some in kilograms, some in stones. Totally different numbers. If we're trying to lose weight, all the matters is that the specific number we're watching is gradually moving downward, in amongst daily fluctuations.
You're doing fine. You've lost 5 pounds!8 
Chances are neither is correct. Your best bet is to pick one and stick with it (I would recommend the new one).
You can check your scale next time you have a doctor's appointment. Just before you leave the house step on the scale wearing exactly what you will be wearing on the Dr.'s office scale. Compare with your weight at the Dr.'s office. My scale is consistently within 1/2 lb of the doctor's scale so I consider it accurate enough.3 
I check mine using a 15 pound dumbell. Its 2 ounces off but otherwise accurate and always says 15.2 when Im doubting the accuracy. I also have a weight watches scale3

When you have a watch, you always know what time it is; when you have two, you can never be sure.12

I have two scales. One was on the fritz, and I got a new one. The old one is working again, and that's the one I use. The new one shows a pound less, and it's really consistent.
There's a balance at my office. Sometimes to make sure my scale(s) are still accurate, I'll weigh myself before I head to work, then get on the balance before I even have any coffee. Guess what? It's pretty much right in between my two scales. I also can check before I run home for lunch. It's just a doublecheck, but it's been pretty consistent. My old analog spring scale was wildly inaccurate even if I zeroed it out. So there's surely a way to check if you want. The main thing, as has been pointed out here, is to pick one and observe how it changes.
Wait! I know what happened! You said when you started you were 11 stone 11 pounds. Well, you just started with the new scale, so it must think you're at your starting weight. <just kidding>0 
Do you have a food scale? I would weigh something heavy on it, at least a few pounds. Then I would weigh it on the scales for people and compare the numbers.0

Do you have a food scale? I would weigh something heavy on it, at least a few pounds. Then I would weigh it on the scales for people and compare the numbers.
This may create confusing results because even something that's relatively heavy for a food scale is going to be near the bottom of the measurement range of a body mass scale. It's probably LEAST accurate there or near the top of the range, just like most other scales. My kitchen scale goes to eleven Pounds that is. About five kilos. They will always have the same precision  1.0 gram for my kitchen scale and 0.2 pounds for my body mass scale. I just don't think they'll be as accurate near the low or top end. I reckon I could test my two scales that way with some plate weights.
I would be interested to find out if the accuracy of my body mass scale changes at different weights. I know it's been pretty consistent as I've lost weight and maintained, but that's "only" a 30pound difference. I assume the balance scale at my office is precise AND accurate. It might be fun to have one, but they are so dang big, and I really don't need it.1 
Yep, as mentioned. Scale readings should be relative, not absolute. This means that which scale you use doesn't matter as long as its the same scale each time.
If scale 1 says 120lbs today and 119lbs next week and scale 2 says 122lbs today and 121lbs next week you've lost 1lb.
The problem comes when you start switching scale. Gong from scale 1 to scale 2 will make your 1lb loss look like a 1lbs gain and going from scale 2 to scale 1 will exaggerate your 1lbs loss to a 3lb loss.1 
The accuracy of scales, unless they have been professionally calibrated, likely are not precise. Whether for body weight or food. Pick a scale and stick with it. Small inconsistency’s are negligible.0

If you have bought a new scale, just stick to using the one scale, there is no point in comparing the two of them.
Test the accuracy of your new scale with something that you know is a fixed weight (like a dumbbell) and if all is well just keep using the one and stop comparing the two.1 
Either one or the other or neither are accurate.
Unless you have access to a properly calibrated scale the only way would be to calibrate it yourself with a known weight that is close to your bodyweight. Calibrating with a light weight really only tells you the accuracy at or near to the light weight. That a scale might be accurate at say 20lbs is no guarantee it's also accurate at 160lbs.
BTW  cost is not a great predictor of accuracy. My £20 ones were accurate to a tenth of a pound and my £80 ones were out by 2lbs when tested against a properly calibrated scale in a sports science lab.2 
This is obvious:
The lighter scale is always correct.
6 
I recently got a new scale that weighs me 2.4 lbs more than my old scale. The new scale is more consistent. By that I mean, two readings in a row are the same. My old scale could vary by a pound or more. I prefer consistency, even though I have no idea which is more accurate.
So my solution was to update all of my former weigh ins (and my starting weight) here on MFP and on the Libra app. Now they show the correct loss.
It took me a few days to get over the disappointment of the number increasing. Don't let anyone belittle that feeling. While it might just "be a number", it still sucks to see it go "up".
Hugs!2 
I recently got a new scale that weighs me 2.4 lbs more than my old scale. The new scale is more consistent. By that I mean, two readings in a row are the same. My old scale could vary by a pound or more. I prefer consistency, even though I have no idea which is more accurate.
So my solution was to update all of my former weigh ins (and my starting weight) here on MFP and on the Libra app. Now they show the correct loss.
This is some serious attention to detail! I would have just made the switch and left the old data as it was. I might put an asterisk in my spreadsheet, kind of like I did when I realized my height had shrank as I aged, and my BMI magically went up since I was no longer my old height. I think you're right that the new scale is the one to use because it's more consistent  technically a higher precision. Whether or not it's accurate you can tell by comparing it to something you know is correct.It took me a few days to get over the disappointment of the number increasing. Don't let anyone belittle that feeling. While it might just "be a number", it still sucks to see it go "up".
Tell me about it! Scales are just goofy.
I had a little slow spike where over a week I gained five pounds. I know I didn't really gain all that, but whatevah. It was pretty steady and going the wrong way, and I figured I'd address it. The next day (two days ago) 0.4 pound came back off, then the yesterday another 0.2 OK, so I'm back down by about a half pound. I was feeling a little dehydrated yesterday and had several pints of water pretty soon after getting up, and I kept hydrating all day. I was hoping to continue that slow trend again today getting back to where I was last week maybe some time this weekend or next week. Well....
I got on the scale today, and I'm down 2.6 from yesterday. I'm still up two pounds from ten days ago, but maybe I'll be back there in another couple days.
When I get to work and get on the balance scale, I usually set it for the weight I think it will say based on what my scale said in the morning. I'm usually right on within a half pound even though I wear different shoes/clothes and maybe had some water.
Scales are just goofy.
1 
I recently got a new scale that weighs me 2.4 lbs more than my old scale. The new scale is more consistent. By that I mean, two readings in a row are the same. My old scale could vary by a pound or more. I prefer consistency, even though I have no idea which is more accurate.
So my solution was to update all of my former weigh ins (and my starting weight) here on MFP and on the Libra app. Now they show the correct loss.
This is some serious attention to detail! I would have just made the switch and left the old data as it was. I might put an asterisk in my spreadsheet, kind of like I did when I realized my height had shrank as I aged, and my BMI magically went up since I was no longer my old height. I think you're right that the new scale is the one to use because it's more consistent  technically a higher precision. Whether or not it's accurate you can tell by comparing it to something you know is correct.
2.4 lbs was pretty significant since my entire goal is a 20 lb loss.
I have no idea what would be accurate. None of my doctors use calibrated scales  I've asked. And I don't belong to a gym.
1 
I hate doing this to the person who just spent a lot of time back changing data.
And the reality is that there is no guarantee as to which scale is more correct, so you may well have done the right thing.
But I much prefer an honest scale that changes the value to show what it actually detects, as opposed to the vast majority of scales out there that exhibit fake (or if you want to be more charitable, programmed) consistency.
Grab yourself a small cup of coffee that you weigh, with the cup, first at 100g and then at 150g to verify (and then at much higher weights to see what the limits are)
Weight yourself without and with the cup. If no difference (100g should be at least 0.2lbs in the decimal section; 150g 0.3lbs) then you know that you're dealing with fake consistency.
Solution is to weigh holding a known object, and the next time without, alternating. I used to have a 4lb water bottle that I would periodically reverify and replenish using my kitchen scale. Now I have a scale where a quick battery pull reinitializes it before I weigh myself1 
Do you have a food scale? I would weigh something heavy on it, at least a few pounds. Then I would weigh it on the scales for people and compare the numbers.
This may create confusing results because even something that's relatively heavy for a food scale is going to be near the bottom of the measurement range of a body mass scale. It's probably LEAST accurate there or near the top of the range, just like most other scales. My kitchen scale goes to eleven Pounds that is. About five kilos. They will always have the same precision  1.0 gram for my kitchen scale and 0.2 pounds for my body mass scale. I just don't think they'll be as accurate near the low or top end. I reckon I could test my two scales that way with some plate weights.
I would be interested to find out if the accuracy of my body mass scale changes at different weights. I know it's been pretty consistent as I've lost weight and maintained, but that's "only" a 30pound difference. I assume the balance scale at my office is precise AND accurate. It might be fun to have one, but they are so dang big, and I really don't need it.
For grins, I just confirmed what I suspected. I took a 3 pound dumbbell weight and put it on one of my scales. It read 0.0 pounds. I reset it and put another one on (total of six pounds). It read 0.0 pounds. I repeated this with my other scale with the same result. So there's a lower limit of what it will even register, never mind how accurate.
For even MORE grins, I weighed myself, then weighed myself again with a 3 pound weight, and again with both 3 pound weights. One scale showed the additional three pounds as 2.8 pounds and the additional six pounds as exactly 6.0 pounds. The other scale showed the extra three pounds as 3.4 pounds and the extra six pounds as 6.6 pounds.
So all this just supports what many of us say often; that number on the scale only means so much on its own. Looking at a longer term trend is way more important, and those little fluctuations from day to day might not even exist!
I then, for even MORE grins put each plate on my kitchen scale. One was exactly 3.0 pounds, one appeared to be a couple tenths of an ounce more than that, and putting them both on (which should be close to midrange of the scale) was a little more than six pounds.3 
Prefer water weighed on kitchen scale since weights can be a bit off too of course calibrating the kitchen scale....1
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