Sorry for the awkward way to express this but I don't know about a standardized way to calculate man hours (though I'm sure there is one somewhere).

Hehe. Let me introduce you to the most important skill of project management that they _never_ teach at Universities (and we wonder why so many business projects are late) - Take that number and multiply it by 0.8. Then, when scheduling tasks, calulate the number of man hours you think they'll all take and double that number.