Estimate pressure drop through a pipe from flow rate, pipe length, inside diameter, fluid properties, pipe roughness, and minor losses. Results include PSI, kPa, bar, feet of head, meters of head, velocity, Reynolds number, and friction factor.
Flow and pipe size:
The calculator converts flow and inside pipe diameter into fluid velocity.
Friction loss:
It estimates Reynolds number, friction factor, and straight-pipe pressure drop.
Minor loss:
It adds optional K-value losses for fittings, valves, bends, filters, entrances, and exits.
A pipe pressure drop calculator is useful for plumbing, irrigation, pump sizing, water supply lines, hydronic systems, fluid transfer, pressure loss checks, and comparing pipe diameters.
This calculator gives an estimate. Real piping systems may require detailed design, exact pipe data, and professional review.
This calculator uses a Darcy-Weisbach style estimate:
ΔP = f × (L ÷ D) × (ρ × v² ÷ 2) + K × (ρ × v² ÷ 2)
Pipe pressure drop is caused by friction between the fluid and pipe wall, plus added losses from fittings, valves, bends, filters, and restrictions.
Yes. Smaller inside diameter increases velocity and can greatly increase pressure drop for the same flow rate.
Yes. A longer pipe creates more friction loss, so pressure drop increases as pipe length increases.
A minor loss K value represents extra pressure loss from fittings, valves, bends, entrances, exits, filters, reducers, and other restrictions.