Every guy is different. Some guys heal fast and some guys heal slow, and there really isn't a way to tell which way any individual guy will lean.
That said, both the circumstances of the breakup and his current situation can at least give you some hints as to how he's doing and how long it'll be before he's in dating shape.
If the breakup was sudden and unexpected, it's a much bigger blow than a relationship whose end was expected. If it was because of cheating or lying, it is that much worse. Because you said that his girlfriend "broke his heart," I'm willing to bet that the breakup was out of the blue. So that certainly doesn't help him.
In terms of his current situation, if he's still stuck in "I can't live without her and I miss her everyday," then he's in no condition to have a meaningful relationship with someone else. The best way to tell if he's in that mindset is to ask his friends, and keep track of him on Facebook. If his friends say he still cries himself to sleep and his Facebook status is constantly sad song lyrics, he needs more time.
Three months might be enough time. Three months might not be enough time. There's just no way to tell for sure. But think about the breakup and figure out his current mindset and you'll at least get a good idea.