Here you will find a handy calculator for determining standard dimensions of UNC, UNF, and ISO threads. We use this calculator almost anytime we have thread milling operations, especially when making custom threads that must still conform to UNC/UNF/ISO standards.
Also included here is a calculator that will determine the ideal wire size and ideal measurement of a given thread using the "3-wire method".
Fields in yellow are to be filled in by the user with numerical values and fields in blue populate automatically to provide relevant data.
For UNC and UNF threads, please remember that "pitch" is the distance between threads, not the number of threads in an inch! for example, a #8-32 screw has 32 threads per inch. The pitch would be 1 divided by 32.