Estimate plumbing pressure drop through a water supply line. Enter starting pressure, fixture flow, pipe length, pipe size, pipe material, fittings, and elevation rise to estimate PSI drop, outlet pressure, kPa loss, and head loss.
Starting pressure:
Enter the pressure before the plumbing run, such as pressure at the meter, pump, tank, or supply point.
Pipe and fixture flow:
Enter the expected water flow and the inside pipe diameter. Higher flow through smaller pipe increases pressure drop quickly.
Fittings and elevation:
The calculator adds estimated losses for elbows, tees, valves, extra restrictions, and vertical elevation rise.
A plumbing pressure drop calculator is useful for water supply lines, bathroom fixtures, kitchen fixtures, irrigation branches, hose bibs, well systems, booster pumps, long pipe runs, and pressure troubleshooting.
This is an estimate for planning and comparison. Actual pressure depends on real pipe ID, fixtures, valves, meters, regulators, filters, and flow conditions.
This calculator estimates plumbing pressure drop with:
Total Drop = Friction Drop + Fitting Drop + Elevation Drop
Plumbing pressure drop is caused by pipe friction, high flow, small pipe diameter, long pipe runs, fittings, valves, filters, restrictions, and elevation rise.
Smaller pipe can create more pressure drop when water is flowing. Static pressure may be similar, but pressure at the fixture can drop during use.
Fresh water loses about 0.433 PSI for every foot of vertical rise.
Yes. Elbows, tees, valves, stops, filters, and fittings add minor losses that reduce available pressure at the fixture.