Motor HP to Torque Calculator

Torque Calculation Formula:

\[ Torque\,(lb\text{-}ft) = \frac{HP \times 5252}{RPM} \]

Torque:

Unit Converter ▲

Unit Converter ▼

From:	To:

1. What is the HP to Torque Formula?

The formula to calculate torque from horsepower and RPM is a fundamental equation in mechanical engineering. It relates these three key parameters of rotational power systems.

2. How Does the Calculator Work?

The calculator uses the standard torque formula:

\[ Torque\,(lb\text{-}ft) = \frac{HP \times 5252}{RPM} \]

Where:

\( HP \) — Horsepower (mechanical power)
\( RPM \) — Revolutions per minute (rotational speed)
5252 — Conversion factor (derived from the relationship between HP, RPM, and torque)

Explanation: The formula shows that torque is inversely proportional to RPM when horsepower is constant. The constant 5252 comes from the fact that 1 HP equals 550 foot-pounds per second, and there are 60 seconds in a minute (550 × 60 ÷ 2π ≈ 5252).

3. Importance of Torque Calculation

Details: Torque is crucial for determining the twisting force of a motor or engine. It's essential for sizing motors, designing mechanical systems, and understanding performance characteristics.

4. Using the Calculator

Tips: Enter the horsepower value and the RPM at which you want to calculate the torque. Both values must be positive numbers. The calculator will compute the torque in pound-feet (lb-ft).

5. Frequently Asked Questions (FAQ)

Q1: Why is 5252 RPM significant in HP-torque curves?
A: At 5252 RPM, torque (lb-ft) and horsepower are numerically equal because of the conversion factor in the formula.

Q2: Can I use this for electric motors?
A: Yes, this formula works for any rotational power system, including electric motors, internal combustion engines, etc.

Q3: What are typical torque values for motors?
A: Torque varies greatly by motor size and type. Small motors might produce 1-10 lb-ft, while large industrial motors can produce thousands of lb-ft.

Q4: How does torque relate to acceleration?
A: Higher torque at a given RPM generally means better acceleration capability, as torque is the rotational equivalent of force.

Q5: What if my RPM is zero?
A: The formula becomes undefined at zero RPM. Motors produce maximum torque when stalled (0 RPM), but this calculator can't compute that value.