There has been a fair amount of discussion about prop selection over the past day or so - many times people have gone off to do some calculations.
There are a few online tools that will do the job but I decided to write a little executable that will do the job for you on your own PC.
It has a couple of improvements over the online ones I've found - mainly in the interface.
You will need to have installed .NET Framework 2.0 before you can run it (this can be got as part of the normal windows update or downloaded from here
(you should have this anyway or you cant run any apps writen in microsoft .NET)
Once you have the .NET Framework just download PropCalc.zip from here
and unzip it anywhere you like and double click it to run it.
Once you have it running simply fill in the details that you know and click the = sign under the detail that you don't know - you can enter speed in knots, mph or kph. Easy as that.
It will calculate :-
1) SPEED from RPM, GEAR RATIO, PITCH and SLIP%
2) RPM from GEAR RATIO, PITCH, SLIP% and SPEED
3) GEAR RATIO from RPM, PITCH, SLIP% and SPEED
4) PITCH from RPM, GEAR RATIO, SLIP% and SPEED
5) SLIP% from RPM, GEAR RATIO, PITCH and SPEED
If anyone wants any more features adding or needs help using the app post here or drop me a PM.
JK if you want to add this to the downloads section - I'm more than happy for you to do so.