What this converter does
This converter turns a linear speed in metres per second into rotational speed in RPM and back. The link depends on diameter, so enter the wheel, roller or rotor size — a larger diameter needs fewer revolutions for the same surface speed. It updates as you type.
Useful for conveyors, rollers, pulleys and machinery. The default 0.5-metre diameter suits a mid-size roller; enter your own for accurate results.
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 RPM for 5 m/s on a 0.5-metre roller.
rpm = v × 60 ÷ (π × d)5 × 60 ÷ (π × 0.5) ≈ 191 rpmSo 5 m/s on a 0.5-metre roller is about 191 RPM.
The units in this example
Surface or belt speed. For a fixed diameter, higher linear speed needs more RPM.
- 5 m/s, 0.5 m ≈ 191 rpm
- 1 m/s, 0.5 m ≈ 38 rpm
- rpm = v × 60 ÷ (π d)
- diameter matters
Revolutions per minute. Falls as the diameter grows for the same surface speed.
- 191 rpm, 0.5 m ≈ 5 m/s
- 100 rpm, 0.5 m ≈ 2.6 m/s
- v = π d × rpm ÷ 60
- bigger d = fewer rpm