1. What is the HP Torque RPM Formula?

Definition: This formula calculates horsepower based on torque and rotational speed (RPM).

Purpose: It helps engineers, mechanics, and automotive enthusiasts determine engine power output.

2. How Does the Formula Work?

The formula is:

Where:

• \( HP \) — Horsepower
• \( T \) — Torque (pound-feet)
• \( RPM \) — Revolutions per minute
• 5252 — Conversion constant (derived from the relationship between power, torque, and angular velocity)

Explanation: The formula shows that horsepower is directly proportional to both torque and RPM. The constant 5252 comes from unit conversions (1 HP = 550 ft-lb/s).

3. Importance of the HP Calculation

Details: Understanding this relationship helps in engine performance analysis, vehicle design, and mechanical system evaluation.

4. Using the Calculator

Tips: Enter torque in pound-feet and RPM. Both values must be positive numbers.

5. Frequently Asked Questions (FAQ)

Q1: Why is 5252 the magic number?
A: It's the RPM at which torque and horsepower values are equal (when using lb-ft for torque). This comes from unit conversions (1 HP = 550 ft-lb/s).

Q2: What's a typical torque value for cars?
A: Passenger cars typically produce 100-300 lb-ft, while trucks may produce 300-1000 lb-ft.

Q3: Does this work for electric motors?
A: Yes, the formula applies to any rotational power source, including electric motors.

Q4: How does RPM affect horsepower?
A: Since HP is directly proportional to RPM, higher RPM generally means higher horsepower for the same torque.

Q5: What if I know kW instead of HP?
A: 1 HP = 0.7457 kW. You can convert after calculation or adjust the formula to use kW directly.