Surface Speed Calculator
Surface speed of a roller, wheel or drum from its diameter and rpm.
Fill any two fields. The empty one is calculated.
How it works
Each revolution moves the surface one circumference, π × d. Multiply by the
revolutions per unit of time:
v = π × d × n
Worked example. A conveyor drum of d = 100 mm turns at n = 300 rpm →
v = π × 0.1 m × 300 /min = 94.25 m/min (1.571 m/s).
It works the other way too: give it the belt speed you need and the drum diameter and it returns the rpm. For a conveyor this is the speed of the belt, as long as it doesn't slip and the belt is thin compared to the drum.
Unit converters: m/min to ft/min, mm to inches, rpm to rad/s.
Questions
What is the formula for surface speed?
v = π × d × n: the circumference times the revolutions per unit of time. A 100 mm drum at 300 rpm moves its surface at π × 0.1 m × 300 /min = 94.25 m/min.
How do I find conveyor belt speed from motor rpm?
Use the rpm of the drive drum, after any gearbox, and the drum diameter. Without slip the belt moves at the drum's surface speed. For the rpm needed for a belt speed, leave rpm empty.
Is surface speed the same as cutting speed?
Yes, for a turning workpiece or a grinding wheel the cutting speed is the surface speed at the cutting diameter. Machinists often quote it in m/min or ft/min (SFM).