47 miles round trip, but I generally push it past 50 to get the half century. :-) I'm averaging riding about half the commutes--more in the summer and less in the winter (when I'll catch the light rail train for part of the trip one or both ways). It took a while to build up the endurance, with three days in a row the first couple of years too much. I can do five in a row now, but Fri's commute isn't as fast as Monday's.