# Horsepower Calculator – How to calculate horsepower of AC Motor?

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2701 The Horsepower of an AC motor can be known in various ways.

If you know the Wattage of an AC motor, you can calculate horsepower of an AC motor.

You can also calculate horsepower, if you know the torque of the AC motor.

But what would you do if neither wattage nor the torque is known?

You can use this horsepower calculator to find the Horsepower of the large industrial AC Motor used in a crane or hoist.

Not only that, you can know the horsepower of many types of motors, ranging from small motors found on toys and devices such as hair dryers.

No worries – it is ok if you do not know the wattage or torque of the ac motor.

This horsepower calculator can calculate horsepower even if the wattage or torque of a given load is not known.

You can find the horsepower of both single-phase and three-phase AC motors.

## Horsepower Calculator

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How to use the calculator?

• From the drop-down menu, select the phase.
• First, note down the rated voltage and current. Also note down power factor and efficiency. You can find details from the motor’s nameplate.
• Enter the data collected in respective fields.
• The calculator would show automatically the calculated value.

## How to calculate horsepower of AC motor?

### Single Phase horsepower calculation formula

For single-phase, horsepower (hp) is equal to rated voltage (V) multiplied by current multiplied by power factor multiplied by efficiency. Then, divide that result by 746 to get the final result in horsepower. Example: Let us say you have a 230 VAC motor having an efficiency 0.75, a power factor 0.70 and the current is 6 amps. The calculated horsepower of an AC motor is 0.97 hp.

### Three Phase horsepower calculation formula

For three-phase, horsepower (hp) is equal to the square root of three multiplied by rated voltage (V) multiplied by rated current (I) multiply by power factor multiplied by efficiency.  Further, divide the whole result by 746. Example: Let us say you have 415 VAC motor having power factor 0.85, efficiency 0.93, and rated current 726. For this motor, the calculated horsepower of the AC motor is 552.324 hp.