Engine Torque Calculator
Enter every measurement Engine Torque Calculator asks for, then press Calculate. The result stays blank while you are still typing.
Press Calculate after the entries are in.
What Engine Torque is for
Engine Torque Calculator is the page to open when you need engine torque from measurements you already have. It belongs with the other automotive calculators because that is the work this arithmetic supports. Power at the crank for that engine is the engine horsepower. Type the entries first. The result stays hidden until you press Calculate, so a half-finished form never flashes a number you might mistake for the answer.
How to fill in this calculator
- RPM. Enter the value this part of the job needs.
- Horsepower. Enter the value this part of the job needs.
The formula in plain language
Horsepower and torque are tied together by rpm. Torque in pound-feet equals horsepower times 5252, divided by rpm. The quarter-mile estimate uses vehicle weight and the elapsed time: horsepower is about the weight divided by (time divided by 5.825) cubed.
A worked example
300 horsepower at 5,000 rpm is 315 pound-feet. A 3,400 pound car that runs the quarter mile in 13.0 seconds is showing roughly 305 horsepower at the tire.
Displacement, compression, airflow, and the torque curve describe one engine. This engine torque result should be read with carburetor size and lb/hr to cc/min.
Mistakes that move the answer
- The 5252 constant only works with pound-feet and horsepower, not newton-meters.
- A quarter-mile time includes traction. Spinning the tires makes the car look weaker than the engine is.
How to check the result
After Calculate shows the engine torque result, redo the last operation with a pencil using the rounded figures on the screen. Matching that check means the inputs were read correctly. If you edit a label or a sentence in this HTML file, reload the page. The form and this article both live in the file, so the edit is what visitors will read.