Fluid mechanics

Relate pipe flow, velocity and diameter; interpret Reynolds and pressure from head.

Solve one variable in a circular pipe. Choose the unknown; it stays visible so you know what is being calculated.

UNDERSTAND THE HOW

More than a result. An explanation.

Choose one unknown and the tool calculates flow, velocity or diameter for a circular pipe. It includes Reynolds and hydrostatic pressure from a liquid column.

Q = A * v; A = piD? / 4; Re = rho vD / mu
Assumptions and limitations

Indicative SI-unit result. It does not calculate head loss or size an installation: losses depend on length, roughness, fittings and valves.

A simple example

A 100 mm pipe carrying water at 2 m/s conveys approximately 15.71 L/s.

Are my inputs stored?

No. Processing stays in your browser. Only tool IDs and timestamps are kept in your recent history; password generation is excluded.

Formula visible · Updated September 8, 2026

Methods, limitations and contact

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