What can Bernoulli's equation solve?

With enough known values, it can estimate pressure, velocity or elevation between two points in ideal steady flow.

Why does pressure drop when velocity rises?

In the ideal model, more kinetic head leaves less pressure head if elevation and total head are otherwise unchanged.

Can I use this for real pipe design?

Use it only as a baseline. Real pipe design needs losses, fittings, pumps, roughness and often code or manufacturer data.

Bernoulli Equation Calculator

Solve Bernoulli's equation between two sections for pressure, velocity, elevation or diameter, with head terms, continuity and cavitation warnings.

Liquid

Pressure reference

Cavitation is checked with absolute pressure; gauge inputs add 101.325 kPa.

Solve for at section 2

1 Section 1 (all known)

Pressure at section 1, absolute

Velocity at section 1

Elevation at section 1

Diameter at section 1

2 Section 2 - solve for Pressure at section 2

Elevation at section 2

Diameter at section 2

Velocity at section 2 is computed from equal flow rate through both sections.

Bernoulli equation

Bernoulli's equation expresses conservation of mechanical energy along a streamline for ideal, steady, incompressible flow.

\frac{p}{ρ g} + \frac{v ^{2}}{2 g} + z = constant

The terms are pressure head, velocity head and elevation head.

Model limits

Ideal-flow assumption

The calculator does not include pump work, turbine work, friction losses, minor losses, compressibility or two-phase flow.

Frequently Asked Questions

Sources and References

Calculations are based on the listed reference sources. Links open in a new tab.

Updated: June 2, 2026

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