Conveyor Motor Power Sizing: A Practical Engineering Guide
An undersized conveyor motor trips on overload; an oversized one wastes capital and runs inefficiently at part load. The goal is a right-sized drive with sensible margin.
This guide covers the tangential-force method, drive efficiency, and how to add a service factor.
The formula
P (kW) = (F × v) ÷ (1000 × η), where F is total tangential force (N), v is belt speed (m/s) and η is drive efficiency.
Worked example
With 2000 N of resistance at 1.5 m/s and η = 0.9: P = (2000 × 1.5)/(1000 × 0.9) = 3.33 kW. Apply a 1.15–1.25 service factor, so specify a 4 kW gearmotor.
Choosing efficiency
Typical gearmotor efficiency is 0.85–0.95. Worm drives sit lower; helical-bevel units higher.
Related calculators
Frequently asked questions
Should I add a service factor?
Yes — 1.15 to 1.25 is common to cover startup and uneven loading.
kW or HP for the nameplate?
Check whether the spec is electrical input (kW) or mechanical output (HP) and convert consistently.
This guide is for educational purposes. Always verify against the relevant standard before final design.