Fact Checked by: David Chen, ME & Automotive Specialist
Last Updated: October 2023 | Expert Verified
Determine the mechanical output of your engine with our professional hp torque calculator. Whether you are tuning a vehicle or analyzing industrial motors, this tool solves for Horsepower, Torque, or RPM using the standard relationship of work and time.
HP Torque Calculator
hp torque calculator Formula
$$HP = \frac{Torque \times RPM}{5252}$$
$$Torque = \frac{HP \times 5252}{RPM}$$
Source: Wikipedia – Horsepower Standards | Engineering Toolbox
Variables:
- HP (Horsepower): The rate at which work is performed.
- Torque (lb-ft): The rotational force or “twist” produced by the engine.
- RPM (Revolutions Per Minute): The speed at which the engine crankshaft rotates.
- 5252: The mathematical constant derived from $(33,000 / 2\pi)$.
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What is hp torque calculator?
The hp torque calculator is a vital tool for automotive engineers and enthusiasts. It describes the physical relationship between torque (the force applied to a lever) and horsepower (how quickly that force is moving). In the context of internal combustion engines, these two metrics provide a complete picture of an engine’s performance profile.
Interestingly, at exactly 5252 RPM, the torque and horsepower values will always be identical. This is because of the way the units are defined in the Imperial system. Above 5252 RPM, horsepower will always be higher than torque, and below that mark, torque is the higher number.
How to Calculate hp torque (Example)
- Identify your known variables (e.g., Torque = 300 lb-ft, RPM = 5,000).
- Multiply Torque by RPM ($300 \times 5,000 = 1,500,000$).
- Divide the result by the constant 5252 ($1,500,000 / 5,252$).
- The result is **285.61 HP**.
Frequently Asked Questions (FAQ)
Is torque more important than horsepower? Torque is what gets a vehicle moving (acceleration), while horsepower determines the top speed and sustained work capability.
Why is 5252 the constant? It comes from the definition of 1 HP as 33,000 ft-lb/min divided by $2\pi$ to convert rotation to linear distance.
Can I calculate HP if I only have RPM? No, you need at least two variables (Torque and RPM) to solve for the third (Horsepower).
Does this work for electric motors? Yes, the physics of power and torque apply to electric motors just as they do to gas engines.