Hydronic Pump Head Calculator
Add the pressure losses along the critical hydronic circuit and convert total pressure drop into pump head.
Total pressure drop
10 psi
Pump head
23.1 ft
Pressure drop
68.9 kPa
For a completely closed hydronic loop, do not add static building elevation to the circulator head. Final pump selection requires the design flow and manufacturer pump curve.
Turn the calculation into a complete design workflow
Use the free result as a quick engineering check, then continue into MEPFlow for connected system design, sizing and project calculations.
How the Hydronic Pump Head Calculator Works
A closed hydronic system circulator is selected to overcome friction and component pressure losses around the operating circuit. Static building height is not added as pump head in a closed loop because the fluid rises and falls within the same circuit.
Enter the design-flow pressure drops for pipe and fittings, terminal or coil, boiler or heat exchanger, control valve and other components. The calculator sums the critical path and converts pressure drop to feet of fluid head using specific gravity.
Final pump selection must place the required design flow and head on the manufacturer's pump curve and check efficiency, NPSH where applicable, minimum flow, control strategy and available motor power.
Calculation basis
Head (ft) = Pressure Drop (psi) × 2.31 ÷ Specific Gravity
When to Use This Calculator
- Boiler-loop pump selection
- Chilled-water branch checks
- Heat-pump hydronic circuits
- Critical-circuit pressure summaries
Engineering Checks Before Final Design
- Use pressure drop at actual design flow.
- Do not add static elevation head for a completely closed loop.
- Final selection must be checked on a pump curve.
Frequently Asked Questions
Do I add building height to hydronic pump head?
Not in a completely closed loop. The circulator primarily overcomes friction and component resistance because elevation gained on one side is recovered on the other.
How many feet of head is 1 psi?
For water near standard conditions, approximately 2.31 ft of head per psi. The calculator corrects this by specific gravity.
Which circuit should I calculate?
Use the circuit that produces the highest required pump head at the relevant design flow, commonly called the critical circuit.
Does this select a pump model?
No. It provides the design duty point; use the manufacturer's pump curves for model selection.