Performance Calculator
Horsepower Calculator
Calculate horsepower from torque and RPM, or find peak torque from HP. Convert between HP, kW, and PS (metric horsepower).
Engine Parameters
Or enter your HP to find torque:
Horsepower
at 4,500 RPM
Kilowatts (kW)
192 kW
PS (Metric HP)
261 PS
Torque (Nm)
407 Nm
HP per Litre (if known)
Enter displacement below
HP Benchmarks
The HP formula.
5,252 = 33,000 ft-lbf/min ÷ (2π)
(the conversion constant between
rotational power and HP)
kW = HP × 0.7457
PS = HP × 1.01387
Nm = lb-ft × 1.35582
Why does HP = Torque × RPM / 5252?
Horsepower is the rate of doing work. Power = Force × Distance / Time. For a rotating shaft: Power = Torque × Angular velocity. 5,252 is the conversion constant that makes lb-ft × RPM come out in horsepower units.
What is PS vs HP?
PS (Pferdestärke) is metric horsepower, used mainly in Europe. 1 PS = 0.9863 HP — nearly identical. Most European car specs are quoted in PS; US specs in HP. kW (kilowatts) is the SI unit, used in Australia and some other markets.
Why do torque and HP curves cross at 5,252 RPM?
Mathematically, HP = Torque when RPM = 5,252. This is why the HP and torque curves always intersect at exactly 5,252 RPM on a dyno sheet — it's a mathematical identity, not a coincidence.