Mechanical vs digital scales

I used mechanical scales back when I lived in my old apartment. Now I'm crashing with my parents for a few months until I move to Germany, and I've been using their digital scales. They don't read the same thing.

Digital: 9st 6/5lbs (fluctuates between the 6 and 5)
Mechanical: 130lbs/59kg (which is 9st 2.9lbs)

What one should I believe? Which kind of scale is more accurate? I did get a fright with the digital scales because they kept saying I was gaining 2/3lbs overnight and then losing it again in a couple of days, it really knocked my motivation as well. But if digital scales are the most reliable, looks like I need to rethink my game a little.

Replies

  • savithny
    savithny Posts: 1,200 Member
    I used mechanical scales back when I lived in my old apartment. Now I'm crashing with my parents for a few months until I move to Germany, and I've been using their digital scales. They don't read the same thing.

    Digital: 9st 6/5lbs (fluctuates between the 6 and 5)
    Mechanical: 130lbs/59kg (which is 9st 2.9lbs)

    What one should I believe? Which kind of scale is more accurate? I did get a fright with the digital scales because they kept saying I was gaining 2/3lbs overnight and then losing it again in a couple of days, it really knocked my motivation as well. But if digital scales are the most reliable, looks like I need to rethink my game a little.

    Well, to know that, you'd need to weigh yourself on a calibrated scale and compare that reading.

    Scales get out of alignment and out of whack. They just do. And digital vs. analog matters less than the quality of construction. The most accurate scales you're likely to find are the mechanical balances at old-school doctor's offices, especially if they're regularly calibrated (which they probably aren't).

    All scales have inherent error. Just because they offer a readout in tenths of a pound doesn't mean they are *accurate* to a tenth of a pound. You need to look at the documentation that came with the scale to see what its rated for - although a lot of them simply don't provide it anymore. Look for "Accurate to +/- X." Thermometers still sometimes have this information, which is how you can find out that even if your digital thermometer tells you you have a temp of 101.4, it's actually only accurate to the nearest .5 degree, meaning the actual value could be anywhere from 99 to 102.
  • allshebe
    allshebe Posts: 423 Member
    My (digital) scale weighs differently if I move it to a different room or even a different spot on the floor in the same room. I think the only scales that are truly accurate are the big ones with the balance weights you see in your doctor's office (or sometimes at a gym). Don't worry too much about the number. Also consider changes in measurements and the fit of your clothes (maybe pick one outfit that is on the snug side now as your "standard" - put it on once a week or so and monitor the change in fit - when it's loose, pick a new outfit - alternatively, take your picture in a full length mirror, in the same pose(s) once a month and note the positive changes.
  • RedVelvetCurls
    RedVelvetCurls Posts: 304 Member
    Both of you have given me much to think about, thank you very much for the input. Very informative!

    Regarding my mechanical scales, they're only about 3 years old (parents have had the digital ones for about 5 or so years), so I'm thinking I should maybe stick to what I'm used to. I don't want to freak out over my parents' scales and lose more weight than I really need to. I think I will ask my doctor to weigh me when I go for my appointment in a couple of weeks, so I can get another perspective.

    I'll also do the outfit thing. I've recently been able to get into a pair of size 10 jeans, so I'll see how baggy they get as time goes on. I'll also do my body measurements and check inches lost.
  • Quilled
    Quilled Posts: 69 Member
    A lot of scales will be off right from the start. Unfortunately its tough to tell how far they are off because of how much our weight fluctuates during the day (I go up and down 3-4lbs during the day), and because of the different circumstances when we weigh ourselves.

    I think the best you can do is just before you leave for your doctors, put on whatever clothing you plan to wear at the office then stand on your mechanical scale. Write down the number and put it in your purse/pocket. When you get the doctors office and they weigh you again write down that number. This will give you the difference in the doctors scale and the scale you have at home. Most mechanical scales can be adjusted from the back (usually a tiny little black circle that you can turn). You can turn that circle and it will move up the line to wherever you want. So if the doctors office says your scale says you weigh 5 more lbs than you do then you can turn it back 5lbs if it says you are 10 more then you can bump it up 10. Whenever you go back to your doctors you can use a similar method to keep the scale around the same.

    However, at the end of the day how much you weigh is just a number so being off by 5lbs isnt going to be the end of the world, its more about how you look and feel.
  • kingscrown
    kingscrown Posts: 615 Member
    I think you can believe them both. No they don't weigh the same, but take the first weigh in as your base line and then set your goals from there. I have both, so I can pick one. I don't feel it matters which as long as one is consistent.
  • jemimasmum
    jemimasmum Posts: 249 Member
    I am soo much shallower than other posters.. which ever weighs lighter!!
  • lcfairbairn74
    lcfairbairn74 Posts: 412 Member
    I think you can believe them both. No they don't weigh the same, but take the first weigh in as your base line and then set your goals from there. I have both, so I can pick one. I don't feel it matters which as long as one is consistent.

    I would go with this! However, if you are only talking about a few weeks, I would just stick with your eating and exercise regimen and not worry about the scales at all personally.
  • anaconda469
    anaconda469 Posts: 3,477 Member
    It is nice to get some type of accuracy for the MFP reports. My digital can give me 3 different readings in a 6 minute period +/- 6 lbs. I weigh in every Monday right after getting out of bed and going to the bathroom. So I take the given weight and subtract 2 lbs. That might be the right way, but after testing it is closer to accurate after my last doctor visit last week.
  • adrylong
    adrylong Posts: 29
    My husband and I have been suspecting that our digital scale was off. This morning I decided to put an unopened bottle of laundry detergent on it, to see what it would say it weighs. I converted that ounces to pounds and discovered the scale was off by 1.3 lbs. You might want to do something like that to check your scale out.
  • crisbabe81
    crisbabe81 Posts: 170
    My husband and I have been suspecting that our digital scale was off. This morning I decided to put an unopened bottle of laundry detergent on it, to see what it would say it weighs. I converted that ounces to pounds and discovered the scale was off by 1.3 lbs. You might want to do something like that to check your scale out.

    I did this but weighed a 35lb dumbell, it said it weight 35.8 haha. I changed my batteries in my scale and did the same test over, the dumbell weighed 35.4, so it semi corrected it's self with new batteries... I found that odd. I still log the number on the scale so I don't drive myself nuts.

    OP, as others have said don't focus so much on the numbers but how you look/feel. The scale can fluctuate so much based on water retention. Just use it as a guideline for your progress. :)