It'll really vary depending on the toughness of your beard, how well you strop and how well you look after the razor.

A tough beard, bad stropping and a humid environment will all shorten the time it takes for a razors edge to deteriorate.

That said, anything from 10 or 15 shaves upward to 30 or 40 seems to be about the range from what I've read. I get about 20 shaves before I have to go back to the hones I've found.

The acid test is how it shaves though. If the razor pulls, doesnt remove hair or you find that you have to start using more pressure to get a good shave, then its time to hone the razor.

Good luck and keep us posted!