This is about weighing a cat at home.

I just bought a Berkley fish scale (FS2). It weighs items up to 20
pounds, the weight range should be perfect for cats. It is a small
handheld device with a hook on it (the link is below in my
signature area). The price said $16 but they charged me only $8 on
sale. It might be a discontinued product.

So my first attempt to put Kitty into an ordinary plastic grocery
bag went very well. He has come a long way from being very timid.

Then I just put the plastic bag loops on the hook and held up the
fish scale with the cat underneath. Easy as pie.

I need to get some worm medicine for Kitty and did not want to
drag him to the veterinarian (we are in the process of taking care
of any fleas). That's why I bought the scale. I looked around and
decided on the fish scale. Bathroom scales are probably not very
accurate at very low weights. There might be exceptions. A
children's scale might do. Postal scales or another possibility.
Kitchen scales are probably usually too light duty.

For what it's worth:
I put Kitty into the plastic bag feet first. If you didn't already
know... putting a cat feet first into a container, like pulling a
cat down from a shelf butt first, works much better than the other
way around (trying to put them in head first or pull them down
head first).

Other suggestions for weighing cats at home are perfectly welcome
by me in this thread.

Take care, have fun