Hidroteknik Calculators
Hydraulic Motor Power & Torque Calculation
The power a hydraulic motor produces depends on system pressure and flow; its torque depends on displacement and the pressure drop across it.
⚙ Open the Hydraulic Calculator →Power & Torque Formulas
Hydraulic power
P (kW) = p (bar) × Q (L/min) / 600
Torque
T (Nm) = Vg (cc/rev) × Δp (bar) / 62.83
Speed
n (rpm) = Q (L/min) × 1000 / Vg
Units
| Quantity | Symbol | Unit |
|---|---|---|
| Pressure | p, Δp | bar |
| Flow | Q | L/min |
| Displacement | Vg | cc/rev |
| Power | P | kW |
| Torque | T | Nm |
Worked Example
Given: Flow Q = 40 L/min, pressure p = 200 bar; motor displacement Vg = 250 cc/rev, Δp = 180 bar.
1) Power: P = 200 × 40 / 600 = 13.3 kW
2) Torque: T = 250 × 180 / 62.83 = 716 Nm
3) Speed: n = 40 × 1000 / 250 = 160 rpm
Frequently Asked Questions
What is the hydraulic power formula?
P (kW) = p (bar) × Q (L/min) / 600. This is the fluid power from pressure times flow.
What determines torque?
Torque depends on motor displacement and pressure drop: T = Vg × Δp / 62.83. Larger displacement gives more torque.
How is this different from mechanical power?
The above is hydraulic power. Mechanical output power is found by multiplying by the motor's overall efficiency (typically 0.85–0.92).