Circulating Pump Head Calculator

Size pumps for hydronic circuits with fewer surprises. Add pipe fittings and fluid details accurately. Get total head power and losses in minutes securely.

Inputs

Closed loops often cancel elevation head.
Use actual internal diameter for best accuracy.
Include supply and return where applicable.
Roughness affects friction factor and head loss.
°C
Temperature influences density and viscosity.
Use for equipment requiring net pressure rise.
K
Add for coils, heat exchangers, or unknown items.
Useful for open systems or static lift checks.
%
Covers fouling, aging, and uncertainty.
%
Used to estimate shaft power.

Fittings and valves

Fitting Quantity K each
0.6
0.15
2
Tip: For closed-loop hydronic systems, focus on friction and device losses. For open systems, include elevation and required pressure rise.

Example data

Scenario Flow ID Length Material Fluid Fittings (summary) Margin Estimated TDH
Hydronic loop 25 m³/h 50 mm 120 m Carbon Steel Water 20°C 6× LR 90°, 2× gate, 1× strainer 10% Run calculator for exact value
Small branch 5 m³/h 32 mm 60 m Copper Tube EG 30% 30°C 8× 90° std, 2× ball 15% Run calculator for exact value
Open transfer 18 m³/h 40 mm 90 m PVC Water 15°C 4× 45°, 1× check, 1× globe 10% Include elevation to capture static lift

These examples demonstrate typical building circulation cases. Use actual internal diameters, realistic lengths, and verified fittings.

Formula used

Total dynamic head combines friction, minor losses, pressure rise, and elevation. The calculator uses the Darcy–Weisbach method for pipe friction.

Core relationships
A = πD²/4
v = Q/A
Re = ρvD/μ
hf = f(L/D) · v²/(2g)
hm = K · v²/(2g)
hp = ΔP/(ρg)
TDH = (hf + hm + hp + hs) · (1 + margin)
Friction factor
Laminar: f = 64/Re (Re < 2300)
Turbulent (Swamee–Jain):
f = 0.25 / [log10(ε/(3.7D) + 5.74/Re^0.9)]²
ε is absolute roughness from the selected material. Results are best for fully developed flow in round pipes.
Power estimate
Phyd = ρgQ · TDH
Pshaft = Phyd / η
η is pump efficiency entered by the user. Power is indicative and should be checked against pump curves.

How to use this calculator

  1. Enter the required flow rate for your circuit.
  2. Provide internal diameter, total length, and material.
  3. Select fluid type and temperature for realistic properties.
  4. Add fittings and valves, or enter extra K if needed.
  5. Include elevation head only when static lift applies.
  6. Set a safety margin and pump efficiency for power output.
  7. Click Calculate, then download CSV or PDF if required.

For critical designs, validate inputs and compare with manufacturer pump curves. Always account for strainers, coils, control valves, and heat exchangers.

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Important Note: All the Calculators listed in this site are for educational purpose only and we do not guarentee the accuracy of results. Please do consult with other sources as well.