Horsepower Calculator

Understanding Horsepower Calculations

What is Horsepower?

Horsepower (HP) is a unit of measurement for power, originally developed by James Watt to compare the output of steam engines with the power of draft horses. Today, it's commonly used to measure the power output of engines and motors.

How to Calculate Horsepower from Torque and RPM

The fundamental formula to calculate horsepower when you know the torque (in pound-feet) and RPM is:

This formula works because at 5,252 RPM, torque and horsepower are equal. Below this point, torque is higher than horsepower; above it, horsepower is higher than torque.

Estimating Horsepower from Vehicle Specifications

Our vehicle horsepower estimator uses the following physics formula to approximate engine power based on acceleration:

Where:

• Weight is in pounds (lbs)
• Speed is in miles per hour (mph)
• Time is in seconds to reach that speed

Types of Horsepower Measurements

• Brake Horsepower (BHP): Power measured at the engine's crankshaft
• Wheel Horsepower (WHP): Power measured at the wheels (accounts for drivetrain loss)
• Metric Horsepower (PS): European measurement (1 PS = 0.9863 HP)
• Kilowatts (kW): SI unit of power (1 kW = 1.341 HP)

Why Use Our Horsepower Calculator?

Our tool provides accurate calculations for various horsepower measurements and conversions. Whether you're a car enthusiast tuning your vehicle, a mechanic diagnosing engine performance, or just curious about automotive specifications, this calculator helps you:

• Convert between torque and horsepower
• Estimate engine power based on vehicle performance
• Compare different power measurements (HP, kW, PS)
• Understand the relationship between torque and RPM