Individual hours spent calculation by designer.

I need the formulas for calculating what a designer has done in hours for each month against the units designed. The units have different times needed. So for example: In the month of January, Jeroen Designed 29 P&D in the US, P&D US review 147, Design US 7, design review 1, P&D BE 9, P&D review BE 49, design BE 24, design review BE 0, P&D JP 6, P&D review JP 18, Design JP, Design review JP 0. Each job takes the following in minutes P&D 45mins, Design 20mins, and Review 10mins. I need calculations to show the total hours spent per designer against the time each unit takes. An example: In January, Victoria did 42 P&D US and 2 P&D review....which calculates to roughly 31.83 hours. I need all the formulas to count even those areas that are 0 as I plan to use this for future months. I eventually want to simply punch in the total units in a category and it calculates accordingly.