Enter your Horsepower, Engine Speed (RPM), and preferred Torque Unit to find your Converted Torque Value — or flip the Conversion Type to go the other direction. You'll also get Power in Watts, Torque in N⋅m, and Mechanical Horsepower alongside your result.
Converted Value
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Power in Watts
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Torque in N⋅m
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Mechanical Horsepower
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Horsepower is a unit of measurement for power, representing the rate at which work is done. It was defined by James Watt in the late 18th century to compare engine efficiency with that of a horse. One mechanical horsepower equals 745.7 watts or 550 foot-pounds per second.
Torque is a measure of rotational force, expressed in pound-feet (lb-ft) or Newton-meters (N⋅m). While torque measures the twisting force, horsepower measures how quickly that torque can be applied over time. The relationship is: Horsepower = (Torque × RPM) ÷ 5252.
To calculate horsepower from torque, use the formula: HP = (Torque × RPM) ÷ 5252, where torque is in lb-ft and RPM is the engine speed. For metric units, HP = (Torque in N⋅m × RPM) ÷ 7127. The RPM value is crucial as it determines the power output at that specific engine speed.
The amount of torque that equals 1 horsepower depends on the RPM. At 5252 RPM, 1 horsepower equals 1 lb-ft of torque. At lower RPMs, more torque is needed to produce 1 HP, while at higher RPMs, less torque is required. This is why the RPM value is essential in the conversion.
Yes, RPM is directly related to horsepower. Horsepower is the product of torque and rotational speed. As RPM increases, horsepower typically increases (assuming torque remains constant), which is why engines produce different power outputs at different RPM ranges.
Both torque and horsepower are important but serve different purposes. High torque is beneficial for acceleration, towing, and low-speed performance, while high horsepower is important for top speed and sustained high-speed performance. The ideal balance depends on the intended use of the engine.
There are several horsepower measurements: Mechanical HP (745.7W) is most common in the US, Metric HP (735.5W) is used in Europe, and Electrical HP (746W) is used for electric motors. The differences are small but can affect precision in engineering calculations.
Yes, common torque unit conversions include: 1 lb-ft = 1.356 N⋅m, 1 N⋅m = 0.738 lb-ft, and 1 kg⋅m = 9.807 N⋅m = 7.233 lb-ft. Our calculator automatically handles these conversions when you select different units.