Ideally, you should weigh yourself without clothes or shoes, so that it is only yourself that is being weighed. However, if that is tricky because there's no privacy or it is too cold, you can do this...
- Weigh yourself with the clothes on.
- Get changed into some other clothes.
- Weigh just the clothes that you wore when you were on the scales.
- Subtract the weight of the clothes from how much you weigh with clothes on.
However, if you were only wearing some light underwear and no shoes, it would only be wrong by a little bit, so that's probably the easiest.
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