Motor Horsepower Calculator

Horsepower Formula:

\[ HP = \frac{V \times I \times PF \times \eta}{746} \]

Voltage (V):

volts

Current (I):

amps

Power Factor (PF):

(0-1)

Efficiency (η):

(0-1)

Horsepower (HP):

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Unit Converter ▼

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1. What is Motor Horsepower?

Horsepower (HP) is a unit of measurement for power, commonly used to rate the output of engines and motors. It represents the rate at which work is done. In electrical motors, horsepower is calculated based on voltage, current, power factor, and efficiency.

2. How Does the Calculator Work?

The calculator uses the electrical horsepower formula:

\[ HP = \frac{V \times I \times PF \times \eta}{746} \]

Where:

\( V \) — Voltage (volts)
\( I \) — Current (amps)
\( PF \) — Power factor (unitless, 0-1)
\( \eta \) — Efficiency (unitless, 0-1)
746 — Conversion factor from watts to horsepower

Explanation: The formula converts electrical power (considering power factor and efficiency) to mechanical horsepower.

3. Importance of Horsepower Calculation

Details: Knowing a motor's horsepower is essential for proper equipment sizing, energy efficiency assessment, and performance evaluation. It helps determine if a motor is suitable for a specific application.

4. Using the Calculator

Tips: Enter voltage in volts, current in amps, power factor (typically 0.8-0.95 for motors), and efficiency (typically 0.8-0.95 for most motors). All values must be positive numbers.

5. Frequently Asked Questions (FAQ)

Q1: What's the difference between brake horsepower and electrical horsepower?
A: Brake horsepower (BHP) is measured at the motor's output shaft, while electrical horsepower is calculated from electrical input. This calculator determines electrical horsepower.

Q2: Why is power factor important?
A: Power factor represents the phase difference between voltage and current in AC circuits. A lower power factor means more current is required for the same real power.

Q3: What are typical efficiency values for electric motors?
A: Standard efficiency motors are typically 85-90% efficient, while premium efficiency motors can reach 92-96%.

Q4: Can this calculator be used for three-phase motors?
A: Yes, but you need to multiply by √3 (1.732) for three-phase power calculations.

Q5: How does motor speed affect horsepower?
A: Horsepower is directly related to torque and speed (HP = Torque × RPM / 5252). At the same horsepower, a faster motor produces less torque.