Horsepower Calculator

Enter value and click on calculate. Result will be displayed.
Torque :
pound-foot
Speed :
revolution per minut
Result:
Rotating HP :

What is a Horsepower Calculator?
A horsepower (HP) calculator is a tool used to determine the amount of power an engine, motor, or machine produces. Horsepower is a unit of power that measures the rate at which work is done — essentially how much energy is transferred or converted over time.

The general formula for horsepower is:

But there are different ways to calculate it, depending on the context:

  • Mechanical horsepower (hp):

    where:

    • Torque = Rotational force (in pound-feet or Newton-meters)
    • RPM = Rotations per minute
    • 5252 = A constant that relates torque and RPM to horsepower

  • Electrical horsepower:

    where:

    • V = Voltage (volts)
    • I = Current (amperes)
    • Efficiency = Decimal form of motor efficiency (like 0.9 for 90%)
    • 746 = Watts per electrical horsepower

Why use a Horsepower Calculator?

  • Sizing motors and engines: Ensures you select a motor powerful enough for a job without over- or under-sizing.
  • Measuring performance: Determines how much work an engine or machine can do.
  • Comparing power output: Helps compare different machines’ efficiencies and capabilities.

How does a Horsepower Calculator work?
You input known values like torque and RPM, voltage and current, or force and speed. The calculator then applies the appropriate formula to solve for horsepower.

When to use a Horsepower Calculator:

  • Automotive and mechanical work: Calculating an engine’s power output.
  • Electrical engineering: Determining the power of motors in HVAC, appliances, and industrial systems.
  • Performance tuning: Measuring horsepower changes after modifying engines or machinery.