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Torque Formula:
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Torque calculation from RPM and power is a fundamental mechanical engineering calculation that determines the rotational force produced by an engine or motor. The imperial formula uses horsepower and RPM to calculate torque in pound-feet.
The calculator uses the torque formula:
Where:
Explanation: The constant 5252 comes from the relationship between horsepower, torque, and RPM, where 1 horsepower equals 550 foot-pounds per second and there are 60 seconds in a minute.
Details: Torque calculation is essential for engine design, vehicle performance analysis, mechanical system design, and understanding the relationship between power output and rotational speed in various mechanical applications.
Tips: Enter power in horsepower (HP) and rotational speed in revolutions per minute (RPM). Both values must be positive numbers greater than zero for accurate calculation.
Q1: Why is the constant 5252 used in the formula?
A: The constant 5252 comes from the conversion between horsepower and foot-pounds per minute, where 1 HP = 33,000 ft-lb/min and 33,000 ÷ (2π) ≈ 5252.
Q2: What are typical torque values for different engines?
A: Typical values range from 100-200 lb-ft for small car engines, 300-500 lb-ft for trucks, and 1000+ lb-ft for heavy diesel engines.
Q3: Can this formula be used for electric motors?
A: Yes, the formula applies to any rotating machinery, including electric motors, as long as power is measured in horsepower and speed in RPM.
Q4: What's the relationship between torque and power?
A: Power is the rate at which work is done, while torque is the rotational force. At 5252 RPM, torque and horsepower are numerically equal in this formula.
Q5: Are there metric versions of this formula?
A: Yes, for metric units: Torque (N·m) = [Power (kW) × 9550] ÷ RPM, where 9550 is the metric conversion constant.