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.
15 tools available
No sign-up · no black-box answers
Calculators
Brake Horsepower Calculator
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Applications
Sump Pump Sizing Calculator
Size a sump pump from your actual inflow — measure it with the built-in rise-rate guide or estimate…
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Hydraulics
Pipe Size Selector & Velocity Calculator
Find the velocity, velocity head, and Reynolds number for a flow and pipe, and compare velocity across nominal…
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Applications
HVAC Hydronic Pump Sizing (BTU/h → GPM)
Convert a heating or cooling load and design ΔT into circulator flow and head — with a proper…
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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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