Pump Flow Calculator
The Pump Flow Calculator computes volumetric flow rate using pump shaft power, total dynamic head, pump efficiency, and fluid density. Outputs in m3/s, L/min, and m3/h.
Educational estimate. Calculator results are for planning and information only, not financial, tax, medical, legal, or engineering advice. Verify important decisions with official sources or a qualified professional.
Pump Flow Calculator
Pump Flow Rate from Power & Head
📐 Formula & Method
Pump Hydraulic Power
Rearranged for flow: Q = P × eta / (rho × g × H). P is shaft power in watts, rho is density, g = 9.81 m/s2, H is head in metres, eta is pump efficiency.
📋 How to Use
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1
Enter pump shaft power in kW.
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2
Enter total dynamic head in metres.
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3
Enter pump efficiency and fluid density.
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4
The calculator solves for Q and displays m3/s, L/min, and m3/h.
🧮 Worked Examples
Validation case
5 kW, 20 m head, 75% efficiency, water density 1000 kg/m3.
Pump Flow Calculator — Engineering Reference
This calculator rearranges the standard hydraulic power equation to estimate flow from known shaft power and head.
Use it for educational or preliminary checks only. Actual pump flow must be read from the pump curve at the system duty point.
🔬 Methodology & Accuracy
Formula: Converts kW to W, converts efficiency percent to decimal, and solves the hydraulic power equation for volumetric flow.
Data sources: Standard pump hydraulic power relationship P = rho g Q H / eta.
Last reviewed: June 2026 · General formula used: Pump Hydraulic Power · Accuracy: Results are precise to two decimal places using IEEE-754 double-precision arithmetic. Intended for educational and planning use only.
For informational purposes only. Results are estimates based on the inputs and formulas provided. For financial, tax, medical, or legal decisions, consult a qualified professional. Rates and regulations change — always verify current figures with official sources.