Motor Horsepower (HP) Calculator

Accurate motor horsepower calculations for AC/DC systems

Motor HP Calculator

Compliant with NEMA MG 1 Standards

Results:

Horsepower (HP): 0.00

How to Use the Calculator

AC Single Phase

  1. Select "AC" system type
  2. Choose "Single Phase"
  3. Enter line-to-neutral voltage
  4. Provide current in amps
  5. Input power factor (0-1)
  6. Enter motor efficiency (0-100%)

AC Three Phase

  1. Select "AC" system type
  2. Choose "Three Phase"
  3. Enter line-to-line voltage
  4. Provide current in amps
  5. Input power factor (0-1)
  6. Enter motor efficiency (0-100%)

DC Systems

  1. Select "DC" system type
  2. Enter voltage
  3. Provide current in amps
  4. Enter motor efficiency (0-100%)

Motor Power Fundamentals

AC Motor Power

In AC motor systems, power calculations consider:

  • Phase configuration (Single/Three)
  • Power factor (cosφ)
  • Motor Efficiency (η)

DC Motor Power

  • No phase or power factor considerations
  • Simple V × I calculation for input power
  • Motor Efficiency (η) is crucial for output HP

Key Formulas:

Input Watts (AC Single Phase): W = V × I × PF

Input Watts (AC Three Phase): W = √3 × V × I × PF

Input Watts (DC): W = V × I

Horsepower (HP): HP = (W × Eff) / 746

Calculation Formulas

AC Single Phase (Input Watts):
W = V × I × PF

AC Three Phase (Input Watts):
W = √3 × V × I × PF

DC Systems (Input Watts):
W = V × I

Horsepower (HP):
HP = (W × Eff) / 746

Example Calculation

Three Phase AC Motor:

Voltage: 480V

Amps: 50A

PF: 0.8

Efficiency: 90% (0.9)

Input W = √3 × 480V × 50A × 0.8 = 33255.39 W

Output HP = (33255.39 W × 0.9) / 746 = 40.09 HP

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