Is anybody else having trouble uploading an avatar?

I just figured out how to do close-ups on my camera (after having it for more than 4 years…), so I got a really cool picture of a flower that I want to make my avatar. It’s JPEG, so that’s not the problem…is there some kind of limit on how big the pic can be? I can’t exactly figure out how to change how big it is or what number to check…