Free · formula-visible · US + metric
Pump Calculators
Free hydraulic and pump-sizing calculators — each shows its formula, its units, and a worked example. US and metric.
41 tools available
No sign-up · no black-box answers
Applications
Well Pump Sizing Calculator (Submersible & Jet)
Size a well pump correctly: total head including the pressure-tank cut-out conversion (the term DIYers forget), a submersible-vs-jet…
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Applications
Pool Pump Sizing Calculator
Size a swimming-pool pump the right way: pool volume, required flow for your turnover time, estimated head, and…
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Power & Energy
Pump Energy Cost & VFD Savings Calculator
Estimate annual pumping energy and cost, then compare a VFD against a throttled valve — modelled on the…
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Power & Energy
Motor Sizing Calculator (NEMA & IEC)
Size a pump motor from brake power, service factor, and margin — with the next standard NEMA (hp)…
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Pump Selection
System Curve & Duty Point Finder
Find a pump’s real operating point: fit your pump curve, build the system curve H = H_static +…
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Pump Selection
Affinity Laws Calculator (Speed & Impeller Trim)
Scale pump flow, head, and power for a change in speed or impeller diameter using the affinity laws,…
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Hydraulics
Friction Loss Calculator (Hazen-Williams)
Calculate water friction head loss with the Hazen-Williams equation from flow, pipe size, length, and the C roughness…
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Hydraulics
Friction Loss Calculator (Darcy-Weisbach)
Calculate pipe friction head loss and pressure drop with the Darcy-Weisbach equation — showing velocity, Reynolds number, friction…
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Hydraulics
NPSH Available (NPSHa) Calculator
Calculate net positive suction head available from altitude or vessel pressure, liquid temperature, static head, and friction —…
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Power & Energy
Pump Power Calculator (Hydraulic, Brake & Motor)
Calculate hydraulic (water) power, brake power at the shaft, and electrical motor input — in HP and kW…
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