Estimate electric motor efficiency from output power and input power. Calculate efficiency using horsepower, watts, kilowatts, amps, volts, phase type, power factor, and motor losses.
Output power:
The calculator uses horsepower, watts, or rated load to estimate useful motor output power.
Input power:
Input power can be entered directly or estimated from volts, amps, phase type, and power factor.
Efficiency:
Efficiency is calculated by dividing output power by input power, then multiplying by 100.
A motor efficiency calculator helps estimate how much electrical energy a motor converts into useful mechanical output.
It can help compare motors, estimate losses, estimate operating cost, review energy savings, and understand how efficiency affects input power.
Your result shows motor efficiency, output power, input power, motor losses, horsepower, kW, amps estimate, monthly kWh, monthly cost, yearly cost, and comparison motor efficiencies.
Divide output power by input power, then multiply by 100. For example, 3,730 output watts divided by 4,150 input watts equals about 89.88% efficiency.
Many modern motors operate around 85% to 95% efficiency, but the normal range depends on motor size, design, load, speed, and operating condition.
Some input energy is lost as heat, friction, windage, copper losses, iron losses, and other internal losses.
For real equipment decisions, use the motor nameplate and manufacturer data. This calculator is useful for estimating and comparison.