Screw Lead and Pitch Calculator

About this calculator

A screw thread's pitch is the axial distance between adjacent thread crests, while its lead is the axial distance the screw advances in one complete revolution. For a single-start thread the two are identical, but for a multi-start thread, where two or more parallel helical grooves run side by side around the shaft, the lead equals the pitch multiplied by the number of starts: lead = pitch × number of starts.

Mechanical designers rely on this relationship when specifying lead screws and ball screws for linear-motion systems — 3D printer Z-axes, CNC machine tables, and precision jacks — because a multi-start screw delivers faster linear travel per revolution than a single-start screw of the same pitch, trading some self-locking friction for speed, which matters when choosing between a leadscrew that needs a motor brake and one that holds position under load on its own.

Enter a screw's pitch and number of thread starts and this calculator returns the lead — how far the screw travels along its axis in one full turn.