About the RPM Calculator
Convert between RPM, surface speed and angular velocity for shafts, wheels and tools.
Also known as: revolutions per minute, rpm to rad/s, surface speed to rpm, shaft speed.
How to use this calculator
- Enter calculate.
- The result updates instantly as you type — press Calculate (or Enter) at any time.
- Review the breakdown shown under the main result.
- Use Copy result or Share to save the answer or send a link with your inputs.
Formula
surface speed = π × d × RPM · ω = 2π × RPM / 60
Worked example
Using the values pre-filled in the calculator above:
- Calculate: Surface speed from RPM
- Rotational speed = 1,450 RPM
- Diameter = 100 mm
the calculator returns:
- Rotational speed: 1,450 RPM
- Surface speed: 455.531 m/min
- Radians per second: 151.8436
- Revolutions per second: 24.1667