Posted: Fri Jun 28, 2013 5:43 pm Re: Hi...
You probably won't be able to tell for sure until they're at least a year old, assuming they're not overfed. Some people here have enough experience that they can sex turtles at 2"-2.5", but 4" is the cut-off. If a turtle is male, he often will start showing signs of that around 3"-3.5". My turtle was confirmed male at 3".
A male turtle has long front claws and a big tail.

Bill - RES
Dixie, Georgia, and Scrappy - cats