It may seem deceiving but his body is at least 1" across and his claws are about 2".
Found that one of the new emerald crabs has shed a couple of times (at least) and is now huge! It is the biggest emerald crab I've seen anywhere, and its' claws seem disproportionately big. I'll post some pictures soon. I also found that one of the original emerald crab babies is still doing well and came out to eat some flakes at the same time we discovered the giant one, cool. He's about half the size of a normal emerald crab now, and is starting to turn green, but is still sort of tan now.