Sacramento Sky Ranch has a bunch of free software downloads that help out with various "mechanic's toolbox" functions, so I figured I'd take it to the next level and implement these tools on the web so (a) you don't need to download anything, and (b) you can run 'em from any computer in the universe.
NOTE: These calculations only apply if the torque wrench is aligned with the extension! Please refer to this document for a technical explanation of this principle.