Thank you for the advice everyone! And you're welcome for converting, but I don't know how long it will take me, it's a pretty huge undertaking!
Nifty, that is a good idea for my pottery pendants. They look larger on the neck display than they really are, and I've stated that in my listing, but a picture would be better. One more thing to add to my to do list, lol.
Kristina, people are more used to fractional inches like 1 1/2 inches, rather than 1.5, so that's why I do that.