About

In automotive engineering, Horsepower and Torque are inextricably linked by rotational speed (RPM). Torque measures the twisting force, while Horsepower measures how fast that work is done over time. A common mistake in tuning is maximizing peak HP without considering the torque curve, which dictates drivability.

This tool allows tuners to visualize the relationship dynamically. By adjusting RPM, you can determine the torque required to hit a power target, or calculate the power output from a dyno torque reading. It handles both Imperial (lb-ft) and Metric (Nm) standards.

Formulas

The constant 5252 comes from converting units (minutes, feet, pounds) to match the definition of 1 Horsepower. The formulas are:

{

Torque_lb-ft = HP × 5252RPMTorque_Nm = kW × 9549RPM

Note: At 5252 RPM, HP and Torque (lb-ft) are always equal.

Reference Data

Engine Type	RPM Range	Avg Torque (Nm)	Avg Power (HP)	Characteristic
Large Diesel Truck	1200-2000	2500	500	High Torque / Low RPM
F1 Car (V6 Turbo)	10000-12000	600	1000	High HP / High RPM
Electric Motor	0-5000	800	400	Instant Torque
Street Sport Bike	9000-13000	110	200	Low Torque / High RPM

Frequently Asked Questions

This is a mathematical certainty in the Imperial system. Since HP = (Torque × RPM) / 5252, if RPM is 5252, the equation simplifies to HP = Torque.

The old saying goes: "Horsepower sells cars, torque wins races." Torque is what you feel when you accelerate from a stop. Horsepower is what helps you maintain high speeds.

Yes. 1 Newton-meter ≈ 0.73756 pound-feet. This tool handles the RPM-based derivation, but direct unit conversion is also possible.

Mathematically, division by zero is undefined. Physically, an engine at 0 RPM produces 0 Horsepower, though an electric motor can produce "Holding Torque" at 0 RPM.