Horsepower to Torque Converter

Horsepower and torque are two ways of measuring an engine's performance — and knowing one at a given engine speed lets you calculate the other. Enter your Horsepower or Torque value along with Engine Speed (RPM), then select your preferred Torque Unit and Horsepower Unit to get the converted value. Secondary outputs include Power in Watts, Torque in N·m, and Mechanical Horsepower for easy cross-unit comparison.

Conversion Type *

hp
lb-ft
rpm

Rotations per minute at which the measurement is taken

Results

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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Frequently Asked Questions

What is horsepower and how is it defined?

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.

What is torque and how does it relate to horsepower?

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.

How do I calculate horsepower from torque?

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.

How much torque equals 1 horsepower?

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.

Is speed (RPM) related to horsepower?

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.

What is better to have: torque or horsepower?

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.

What are the different types of horsepower measurements?

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.

Can I convert between different torque units?

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.