Water Pressure Loss Calculator

Estimate water pressure loss through a pipe from flow rate, pipe length, inside diameter, pipe material, fittings, and elevation change. Results include PSI loss, kPa loss, bar loss, feet of head loss, and estimated outlet pressure.

Calculate Water Pressure Loss

Total water pressure loss = pipe friction loss + fitting loss + elevation loss
Your result will appear here.

How the water pressure loss calculator works

Pipe friction loss:
The calculator estimates friction loss based on water flow, pipe length, inside diameter, roughness, and water viscosity.

Fitting loss:
Use the K value to include elbows, tees, valves, filters, hose bibs, reducers, and other restrictions.

Elevation loss:
Water loses about 0.433 PSI for every foot of vertical rise.

Why use a water pressure loss calculator?

A water pressure loss calculator is useful for plumbing runs, irrigation lines, garden hoses, wells, booster pumps, water supply lines, pressure washers, and checking estimated pressure at an outlet.

This calculator estimates pressure loss. Real systems may need exact pipe data, fixture ratings, pump curves, and professional design.

Water pressure loss formula

This calculator estimates water pressure loss with a Darcy-Weisbach style method:

Total Loss = Friction Loss + Minor Loss + Elevation Loss

Water pressure loss calculator tips

Frequently asked questions

What causes water pressure loss?

Water pressure loss is caused by pipe friction, fittings, valves, filters, restrictions, high flow rate, small pipe diameter, and elevation rise.

How much pressure is lost from elevation?

Fresh water loses about 0.433 PSI for every foot of vertical rise.

Does pipe size affect water pressure loss?

Yes. Smaller inside pipe diameter increases water velocity and can greatly increase pressure loss.

Does flow rate affect pressure loss?

Yes. Higher flow rates usually create much higher pipe friction loss and lower outlet pressure.