RPM to Linear Speed Calculator
Convert rotational speed and diameter into linear (surface) speed — for conveyors, rollers, pulleys, wheels, or any rotating surface.
Enter your values
Rotating diameter and rotational speed.
How this calculator works
A point on the surface of a rotating diameter travels one circumference per revolution. Multiplying circumference by rotational speed gives linear (surface) speed:
Where D is diameter in millimeters, N is rotational speed in RPM, and v comes out in meters per second. The calculator also converts this to meters per minute and feet per minute for convenience.
Unit conversion reference
| Quantity | Conversion |
|---|---|
| m/s → m/min | multiply by 60 |
| m/s → ft/min | multiply by 196.85 |
| mm/rev circumference | π × D |
These conversions are applied automatically in the result above.
Frequently asked questions
Is this the same as cutting speed?
The underlying formula is the same, but cutting speed (Vc) specifically refers to the surface speed of a workpiece or tool in machining. Use the dedicated cutting speed calculator if you're selecting spindle RPM for turning or milling.
What diameter should I use for a belt or roller?
Use the effective outer diameter of the rotating component that contacts the surface or material — for a pulley driving a belt, that's the pulley's outside diameter, not its shaft diameter.