HCA: Hermit Crab Association

I saw your chart about the size of crabs and how much space they need. I haven't seen many hermit crabs, so I have no idea how to gauge if they are small or large (or something in between). Any tips for determining where this crab fits?

At the top right of the graphic is a sketched crab that shows that the legspan is what is measured. If you are a quilter, you can put your crab on a cutting mat to see how wide their legspan is!