Probably ought to math that out with waking hours. And add in your commute. And 2000 hours = 38/week. I don't know many folks who work that little, though I supposed vacation days ought to factor into it (the average american takes 4.1). Let's nudge it up to 2400 or so.

2400 hours worked + 260 hours commuting (US avg. is 25.5min - probably average higher in startup cities?) Let's say 17 waking hours (even though people who get 7 hours of sleep are proven to be less effective on a lot of fronts, it's certainly plenty common).

(edit: average hours worked/week in US for salaried workers is 46: http://www.prdaily.com/Main/Articles/Most_employed_Americans...)

2660 / 365*17 = 43%