I just got on the scale completely nude: 165.2 lbs.
Then I got on in athletic shorts, t-shirt, and hat: 166.2 lbs.
Then, I got in jeans. Just jeans, no shirt: 167 lbs.
Clothes have mass. They are a variable which, if not controlled for, can seriously mess with your mind. So, weigh naked or with the same clothes every time. It’ll make things a whole lot easier.