Pump Specific Speed Calculator
Enter pump speed, flow rate, and head. Calculates metric nq and US Ns, with impeller type & application. Export to Excel with live formulas.
Specific Speed (metric nq)
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Specific Speed (US Ns)
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Impeller Type
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Typical Application
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Formula & unit notes
- Metric:
nq = n · sqrt(Q[m³/s]) / H[m]^(3/4) - US:
Ns = n · sqrt(Q[gpm]) / H[ft]^(3/4) - Classification by metric nq (editable in Excel):
- Radial: nq < 30 (high head, low flow)
- Mixed: 30 ≤ nq < 80 (medium head/flow)
- Axial: nq ≥ 80 (low head, very high flow)