Hydraulic Pump Flow Calculator
Calculate hydraulic pump output flow from displacement, speed, and volumetric efficiency.
How it works
- 1Enter the pump displacement in cc/rev — the swept volume per shaft revolution.
- 2Enter the shaft speed (rpm) and the volumetric efficiency to account for internal leakage.
- 3The calculator applies Q = displacement × speed × efficiency and shows L/min, gpm, and m³/h.
Use cases
- Sizing hydraulic pumps for excavators, presses, and machinery.
- Comparing theoretical and actual flow to diagnose worn pump components.
- Selecting a displacement to meet a target circuit flow at a given speed.
Frequently asked questions
How is pump output flow calculated?
Q = displacement (cc/rev) × speed (rpm) × volumetric efficiency. A 32 cc/rev pump at 1500 rpm and 95% gives Q = 32 × 1500 × 0.95 ÷ 1000 ≈ 45.6 L/min.
What is volumetric efficiency?
It accounts for internal leakage past seals and clearances. A new gear pump reaches 90–98%; worn pumps drop below 85%, reducing actual flow.
What is the theoretical flow value?
The flow at 100% efficiency (no leakage). Comparing it with the actual flow measures internal losses — useful for condition monitoring.
Related tools
See all →Find the gear ratio, output speed, torque, and mechanical advantage of a gear pair, in metric or imperial.
Calculate the overall ratio and output speed of a multi-stage compound gear train.
Calculate shaft torque from power and rotational speed in metric or imperial units.
Calculate the mechanical power transmitted by a rotating shaft from torque and shaft speed.