HP to Torque Calculator
Solve for horsepower, torque, or RPM — enter any two values and the third is calculated instantly.
HP / Torque / RPM Solver
Enter any 2 — solve the 3rd
How It Works
Power, torque, and RPM are linked by a fixed formula. The constant 5252 comes from the conversion of horsepower to ft-lb/min and the 2π factor in angular velocity.
How to Use This Calculator
- Enter any two known values — power, torque, or RPM.
- Select the torque unit (lb-ft or Nm).
- Leave the unknown field blank.
- Click Calculate — the missing value is solved.
- The result also shows the Nm equivalent if lb-ft is used.
Worked Example
Reference Table
| Engine | Peak HP | Peak Torque | RPM @ Peak HP |
|---|---|---|---|
| Honda K20 (civic type R) | 306 hp | 295 Nm | 6 500 |
| Toyota 2JZ-GE | 220 hp | 296 Nm | 5 600 |
| Ford 5.0 Coyote | 450 hp | 529 Nm | 7 000 |
| BMW S58 (M3) | 503 hp | 650 Nm | 6 250 |
| GM LS3 | 430 hp | 569 Nm | 5 900 |
| VW 2.0T EA888 | 220 hp | 350 Nm | 4 500 |
| Subaru FA20 STI | 305 hp | 406 Nm | 4 000 |
Frequently Asked Questions
Why does 5252 RPM equal peak HP and torque on a dyno chart?
At exactly 5 252 RPM, the HP and lb-ft torque curves always cross because 5252 is the constant in the formula. It is not a coincidence — it follows directly from the definition of horsepower (550 ft-lb/s) converted through unit algebra.
What is the difference between crank HP and wheel HP?
Crank (brake) HP is measured at the flywheel; wheel HP (WHP) is measured at the driven wheels and is typically 10–20% lower due to transmission, differential, and drivetrain losses.
What is the difference between lb-ft and Nm torque?
1 lb-ft = 1.35582 Nm. To convert, multiply lb-ft by 1.356. Most European manufacturers quote torque in Nm; US manufacturers in lb-ft. The calculator handles both.
Why do diesel engines produce more torque but less horsepower than petrol?
Diesel engines develop peak torque at low RPM (1 500–2 500 RPM) and have a narrow power band. Since HP = torque × RPM ÷ 5252, the lower peak RPM limits peak HP even with high torque figures.
