2 to 3 a day depending on genre and complexity of arrangement. Then about an hour or two of revision the next day.

I also charge by the hour......I will give the client a choice between a 2-4 hour mix for an hourly rate for those budget jobs but explain that if the want the best mix possible to pay by the song which i end i spending way more time ussually than my hourly rate but feel i am not under the clock pressue........................typical mix mix 6-10 hours day one until i am happy with it ...then following day have a client in for final critique for ussually 1-2 hours for final approval,,,....so I would say I average 10-12 hours per song..........but i have also been payed to do a 2 hour mix.......they ussually get what they pay for...not to say you cant get a good sounding mix in a short amount of time ..I feel it takes me quite a while to really get into the fabric of the tune......I feel it is the subtleties that really can make a mix sound like majic!