Pump Head & HP Sizing Calculator

Pump Head & HP Sizing Calculator

Works out Total Dynamic Head (TDH) and motor power for domestic water supply, drainage/sump, fire hydrant, fire sprinkler, HVAC chilled water, and custom pumping systems. Pick a system type below — it pre-fills sensible defaults which you can still edit.

1. Select System Type

2. Flow & Pipe Data

Design Flow Rate

m³/hr L/min L/sec US GPM

Delivery Pipe Internal Diameter (mm)

Pipe Material (sets Hazen-Williams C) uPVC / CPVC / HDPE (C=150) Copper (C=140) Ductile Iron, lined (C=130) MS / GI, new (C=120) MS / CI, old/corroded (C=100) Custom C value...

Custom Hazen-Williams C

Straight Pipe Length (m) total run, pump to outlet

Fittings Allowance +25% of straight length (typical) +15% of straight length (few fittings) +40% of straight length (many fittings/valves) Enter equivalent length manually

Fittings Equivalent Length (m)

3. Head Data

Suction Lift (source below pump; 0 if flooded suction)

Static Discharge Height (m) pump to highest/farthest outlet

Required Residual Pressure at Outlet (bar)

Recommended Max Velocity (m/s) reference only

4. Efficiency & Safety Margin

Pump Efficiency (%)

Motor Efficiency (%)

Safety / Oversizing Margin on Motor Power (%)

Please check inputs — diameter, flow and length must be greater than zero.

Total Dynamic Head

—

—

Recommended Motor Rating

—

—

Flow Velocity in Pipe

—

—

Head Breakdown

Component	Value

Power Breakdown

Stage	kW	HP

Calculations use the Hazen-Williams friction loss formula and standard hydraulic power equations (P_kW = 9.81 × Q(m³/s) × H(m) ⁄ pump & motor efficiency). Results are for preliminary sizing / estimation only — verify against manufacturer pump curves, NFPA 20 / local fire code, and applicable plumbing code before finalizing equipment selection. From MEP Analysis.