Horsepower Calculator

Horsepower Formula:

\[ HP = \frac{Torque \times RPM}{5252} \]

Horsepower (HP):

Unit Converter ▲

Unit Converter ▼

From:	To:

1. What is the Horsepower Formula?

The horsepower formula calculates the power output of an engine based on torque and rotational speed (RPM). It's a fundamental equation in automotive and mechanical engineering used to measure engine performance.

2. How Does the Calculator Work?

The calculator uses the horsepower formula:

\[ HP = \frac{Torque \times RPM}{5252} \]

Where:

\( Torque \) — Rotational force in pound-feet (lb-ft)
\( RPM \) — Rotations per minute (rev/min)
\( 5252 \) — Conversion constant derived from the definition of horsepower

Explanation: The constant 5252 comes from the relationship where one horsepower is defined as 550 foot-pounds per second, and there are 60 seconds in a minute.

3. Importance of Horsepower Calculation

Details: Horsepower is a crucial metric for evaluating engine performance, comparing different engines, and determining vehicle capabilities. It helps in vehicle selection, performance tuning, and mechanical design.

4. Using the Calculator

Tips: Enter torque in lb-ft and RPM in revolutions per minute. Both values must be positive numbers. The calculator will automatically compute the horsepower output.

5. Frequently Asked Questions (FAQ)

Q1: Why is the constant 5252 used in the formula?
A: The constant 5252 comes from the conversion between foot-pounds per minute and horsepower (1 HP = 33,000 ft-lb/min ÷ 2π ≈ 5252).

Q2: What is the difference between horsepower and torque?
A: Torque measures rotational force, while horsepower measures the rate at which work is done. Horsepower = (Torque × RPM) / 5252.

Q3: What are typical horsepower values for different vehicles?
A: Economy cars: 100-150 HP, family sedans: 150-250 HP, sports cars: 300-500 HP, supercars: 500-1000+ HP.

Q4: Can this formula be used for electric motors?
A: Yes, the formula applies to any rotating machinery, including electric motors, though electric motors often have different torque curves.

Q5: How does RPM affect horsepower?
A: Horsepower increases with RPM up to a point, but eventually torque decreases at high RPM, causing horsepower to peak and then decline.