How long before a puppy is house trained?

We have used the crate to house train our puppy (he's 9 months now). At first we were just trying to keep an eye on him and that didn't work at all. I would say we have been crate training him about 3 weeks to a month. He rarely has an accident but we are always running him out to the bathroom. How long before he knows how to hold it until he goes out or can be trusted unsupervised?