Pump NPSH Calculator

Calculate NPSH Available, Check Cavitation Risk, Estimate Pump Head & Power

🔧 Suction Side Parameters

Suction Pressure bar(a) — 1.01325 = atmospheric

Liquid Vapor Pressure bar(a) — 0.0234 = water @ 20°C

Static Head (Suction) m — positive = flooded suction

Suction Pipe Length m

Suction Pipe ID mm

Pipe Roughness

Number of Fittings elbows, valves, etc. (K ≈ 0.5-1.5 each)

Avg. Fitting K-Factor per fitting

Strainer/Filter DP bar (0 = none)

⚙️ Pump & Fluid Properties

Flow Rate m³/hr

Fluid Density kg/m³ (water = 1000)

Dynamic Viscosity Pa·s (water = 0.001)

Pump Efficiency % — typical centrifugal: 60-85%

Safety Margin m — NPSHa must exceed NPSHr by this margin

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The free calculator does single-point NPSH check. The Pro Excel Workbook adds: pump curve database · multi-condition analysis (min/normal/max flow) · automatic NPSHr lookup · parallel/series operation · datasheet generation · viscosity correction (ANSI/HI 9.6.7)

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Pump NPSH Calculator

🔧 Suction Side Parameters

⚙️ Pump & Fluid Properties

📊 NPSH & Cavitation Analysis

📐 Pump Sizing Estimate

📋 Pro Pump Sizing Toolkit — $29