🇮🇳 Performance Calculator
Horsepower Calculator
Calculate power in PS from torque (Nm) and RPM, or find peak torque from a known PS figure. Convert between PS, kW, and HP (imperial).
Engine Parameters
Or enter a known power figure to find torque:
Power
at 4,000 RPM
Kilowatts (kW)
77 kW
HP (imperial)
104 HP
Torque (lb-ft)
184 lb-ft
PS per Litre (if known)
Enter displacement below
Power Benchmarks (Indian market)
The power formula.
9,549 = 60,000 ÷ (2π)
(the conversion constant between
rotational power and kilowatts)
PS = kW × 1.35962
HP = kW × 1.34102
lb-ft = Nm ÷ 1.35582
Why does Power (kW) = Torque (Nm) × RPM / 9,549?
Power is the rate of doing work. Power = Torque × Angular velocity. For a rotating shaft, angular velocity in rad/s = 2π × RPM / 60. Combining the constants gives 9,549 - the conversion factor that makes Nm × RPM come out in kilowatts.
What is PS vs kW vs HP?
PS (Pferdestärke, "metric horsepower") is the unit used on Indian and European car spec sheets. 1 PS = 0.9863 HP (imperial) - nearly identical. kW is the SI unit power is technically measured in, and increasingly shown alongside PS on Indian brochures, especially for EVs.
Why do torque and power curves cross at a specific RPM?
Mathematically, when torque is in Nm and power is in PS, the two curves cross at 7,127 RPM - the point where Nm × RPM / 7,127 numerically equals the Nm value itself. This is a mathematical identity, not a coincidence, and shifts if you plot in kW or HP instead.