Wheel Maker is a special-purpose tool for calculation of bicycle wheel spoke lengths. If you're a professional, hobbyist, or home mechanic interested in developing your own bicycle wheel parameters, this software will quickly calculate the proper length steel spokes based on hub size and circumference or diameter of the wheel. Stretch and torsional effects are considered.
Measurements are in millimeters.
Detailed help and sample wheel data get you started. The author disclaims this as a wheel builder's manual but provides excellent references to aid someone starting out.