トルク - パワー - 速度計算機

Use the formula: T = 9549 × P / n

• T = torque in Nm
• P = power in kW
• n = speed in RPM

This is derived from the fundamental relationship P = T × ω, where ω = 2πn/60 is the angular velocity in rad/s.

Power (kW) and torque (Nm) are related through rotational speed:

P = T × n / 9549

Key insights:

• At constant speed, power is directly proportional to torque
• At constant power, torque is inversely proportional to speed
• Doubling the speed at constant power halves the torque

The constant 9549 (more precisely 9549.2966...) is a convenient conversion factor:

9549 = 60000 / (2π)

It arises from converting RPM to rad/s and watts to kilowatts simultaneously. Using it avoids the need to manually calculate ω = 2πn/60 and convert kW to W.

Multiply kW by 1.341 to get mechanical (imperial) horsepower:

• 1 kW = 1.341 hp
• 1 hp = 0.7457 kW

Note: Metric horsepower (PS/CV) is slightly different: 1 PS = 0.7355 kW. The calculator uses mechanical (imperial) horsepower.

For a given power output, yes — torque and speed are inversely proportional: T = 9549 × P / n.

However, actual machine behavior varies:

• AC induction motors have nearly constant torque up to rated speed, then torque drops at higher speeds (constant power region)
• DC motors can deliver constant torque over a wide speed range with proper control
• Combustion engines have peak torque at a specific RPM, with the torque curve varying by design