Cutting Speed Calculator

Inputs

Solve for

Choose whether the unknown is RPM or cutting speed.

Diameter (D)

Tool diameter for milling/drilling, or workpiece diameter for turning.

Cutting speed (Vc)

Target cutting speed from a reference table or tooling recommendation.

m/min

Default result

Spindle speed(n)

382rpm

Also computed

Cutting speed(Vc)30.48m/min

Method notes 3 notes

RPM = cutting speed ÷ (π × diameter); cutting speed = RPM × π × diameter.
Use tool diameter for milling and drilling; use workpiece diameter at the cut for turning.
Recommended cutting speeds are starting points. Tool material, coating, coolant, rigidity and depth of cut all move the practical value.