in the summer when it is hot and I sweat more then probably only once or twice but in the winter when that isn't the case 3-4 times. I don't sweat much anyway so I'm usually good for a few days with one pair. Plus when I get home from work I generally change right out of them and into either shorts or joggers so I don't wear them for more than a few hours each time anyway. Of course if I do something that actually gets them dirty then it doesn't matter how many times I've worn them they go into the wash at that point.