What this converter does
This converter turns rotational speed in RPM into linear speed in metres per second and back. Surface speed depends on diameter, so enter the wheel, roller or rotor size — a bigger diameter gives more speed per revolution. Type the RPM and read the speed instantly.
Handy for conveyor belts, grinding wheels and rotating machinery. The default 0.5-metre diameter suits a mid-size roller; set your own as needed.
The units it covers
Surface (linear) speed and rotational speed are linked by the diameter — a point on a bigger wheel moves faster for the same RPM, so diameter is required.
View all units & their values
| Unit | Symbol | Value | Mainly used |
|---|---|---|---|
| Linear speed | m/s | v | Surface / belt / rim speed |
| Rotational speed | rpm | N | Revolutions per minute |
| Diameter | m | d | Wheel, roller or rotor diameter |
The formula
Linear speed is the circumference times revolutions per second, so it scales with both diameter and RPM:
v = π × d × rpm ÷ 60Where:
- v = linear speed in metres per second
- d = diameter in metres
- rpm = revolutions per minute
Worked example
Find the surface speed at 300 RPM on a 0.5-metre wheel.
v = π × d × rpm ÷ 60π × 0.5 × 300 ÷ 60 ≈ 7.85 m/sSo 300 RPM on a 0.5-metre wheel is about 7.85 m/s.
The units in this example
Revolutions per minute. More RPM means more surface speed for a given diameter.
- 300 rpm, 0.5 m ≈ 7.85 m/s
- 100 rpm, 0.5 m ≈ 2.6 m/s
- v = π d × rpm ÷ 60
- diameter matters
Surface or rim speed. Rises with both diameter and revolutions per minute.
- 7.85 m/s, 0.5 m ≈ 300 rpm
- 5 m/s, 0.5 m ≈ 191 rpm
- rpm = v × 60 ÷ (π d)
- bigger d = more m/s