Electric Motor Torque Calculator

Electric Motor Torque Formula:

\[ T = \frac{P \times 9550}{N} \]

Torque (T):

Unit Converter ▲

Unit Converter ▼

From:	To:

1. What is the Electric Motor Torque Formula?

The electric motor torque formula calculates the rotational force produced by an electric motor based on its power output and rotational speed. It's essential for motor selection and mechanical system design.

2. How Does the Calculator Work?

The calculator uses the torque formula:

\[ T = \frac{P \times 9550}{N} \]

Where:

\( T \) — Torque in Newton-meters (Nm)
\( P \) — Power in kilowatts (kW)
\( N \) — Rotational speed in revolutions per minute (RPM)
9550 — Conversion factor combining unit conversions and constants

Explanation: The formula shows that torque is inversely proportional to speed when power is constant. The constant 9550 comes from unit conversions (kW to W, minutes to seconds) and the relationship between rotational speed and angular velocity.

3. Importance of Torque Calculation

Details: Accurate torque calculation is crucial for selecting appropriate motors for applications, ensuring proper mechanical design, and preventing motor overload or underutilization.

4. Using the Calculator

Tips: Enter power in kW and speed in RPM. Both values must be positive numbers. The calculator will compute the torque in Nm.

5. Frequently Asked Questions (FAQ)

Q1: Why is 9550 used in the formula?
A: 9550 combines the conversion factors for kW to W (1000), minutes to seconds (60), and the relationship between RPM and radians per second (2π/60 ≈ 0.10472). The exact value is 60,000/(2π) ≈ 9549.3, rounded to 9550.

Q2: What is a typical torque range for electric motors?
A: Torque varies greatly by motor size and type. Small motors might produce 0.1-10 Nm, while large industrial motors can produce thousands of Nm.

Q3: How does torque relate to motor performance?
A: Torque determines a motor's ability to overcome load resistance. Higher torque means better ability to start under load or accelerate heavy masses.

Q4: Can this formula be used for all motor types?
A: This formula works for any rotating machinery where power and speed are known, but actual torque may vary due to efficiency losses, especially at different speeds.

Q5: How does torque change with speed in electric motors?
A: For constant power applications, torque decreases as speed increases. However, many motors have variable torque characteristics across their speed range.