Druid,
Try Googling "propcalc" - it will give you a different set of programs
and some of these, including the freeware excel program named
*PropCalc*, will require input of engine horsepower. In fact, PropClac
requires it in the first entry.
The following is a copy of the first calc page. Some of the entries are
user inputs, some are the calculations. For ex. you put in engine
horsepower and max rpm, and out comes torque, etc.

45 Engine Horsepower
2000 Engine R.P.M. (max)
118 Engine Torque ft/lb

44 SHP - Shaft Horsepower at gearbox output.
3 Enter number of bearings between gearbox output and propeller.
1.50 Enter Gearbox reduction ratio. Eg. 1.5

4.50% Percentage power loss due to shaft bearings.

44 Shaft Horsepower at propeller.
1333 Propeller RPM
172 Propeller Torque ft/lb


Red