About this calculator
This calculator determines the total pressure drop through a piping system including straight runs, fittings, and elevation changes. Use it when sizing pumps or verifying that available pump head is sufficient for a hydronic heating or cooling loop. It adds the horizontal run, vertical drop, and the fittings' equivalent length you enter, applies your friction loss rate to that length, and adds static lift at 0.43 PSI per foot of vertical rise. For a closed loop, where static head cancels out, enter 0 for Vertical Rise.
Use when You need to calculate total pressure loss through a piping system.
Formula ΔP = Vertical Rise × 0.43 + (Horizontal + Vertical Drop + Fittings Eq. Length) × Loss/ft
Variables
Vertical Rise Vertical rise in feetVertical Drop Vertical drop in feetHorizontal Pipe Horizontal pipe run in feetFittings Eq. Length Equivalent length of fittings in feetPressure Loss/ft Friction loss rate in PSI per foot, read for your pipe size and flow
Vertical Rise (ft)
Upward pipe distance in feet (0.43 PSI/ft)
Vertical Drop (ft)
Downward pipe distance in feet
Horizontal Pipe (ft)
Horizontal run length in feet
Fittings Eq. Length (ft)
Total equivalent length of fittings
Pressure Loss (PSI/ft)
Friction loss rate per foot of pipe
Vertical Loss (PSI) —
Horizontal Loss (PSI) —
Total Drop (PSI) —

How is piping pressure drop calculated?

Piping pressure drop is the total loss in fluid pressure as water flows through a hydronic heating or cooling system. It includes friction losses in straight pipe runs, losses through fittings and valves (expressed as equivalent pipe lengths), and static head from elevation changes. The friction loss per unit length depends on flow rate, pipe diameter, pipe material roughness, and fluid properties. For closed hydronic loops, the pump must overcome only the friction losses because the static head cancels out in a closed circuit. For open systems such as cooling towers, the pump must also overcome the elevation difference. Total pressure drop is typically expressed in feet of head or PSI: ΔP (PSI) = vertical rise × 0.43 + equivalent length × friction rate per foot. Pump selection requires matching the pump curve to the system's total pressure drop at the design flow rate.

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