Bernoulli Equation Calculator

Written by Great Medico

Updated September 25, 2026 •2 min read

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Fluid calculations are especially sensitive to density, viscosity, geometry, pressure conventions, and unit systems. Bernoulli Equation Calculator narrows that problem to the relationship used on this page, making the displayed pressure change easier to audit against the inputs and the governing equation.

What this calculator does

The Bernoulli Equation Calculator uses Pressure — position 1, Fluid speed — position 2 to estimate the page’s Pressure change from the fluid-mechanics relationship below. It is meant for a defined geometry and property set, so the useful part is not just the headline number but also whether your density, viscosity, dimensions, pressure reference, and flow convention match the model.

How to use it

Start with the fields that actually drive this result: Pressure — position 1, Fluid speed — position 2. Keep units consistent with the menus beside the fields and avoid mixing values measured under different conditions. After calculating, change one input at a time if you are comparing scenarios; that makes cause-and-effect much easier to see.

How the calculation works

The page uses Bernoulli’s ideal mechanical-energy relation p + ½ρv² + ρgz = constant between two points. With five of the six pressure, velocity, and elevation quantities entered, it can solve the remaining term.

Example

Using the page’s default example (Pressure — position 1 = 200 kPa; Fluid speed — position 2 = 5 m/s), the calculator reports Pressure change of -200,000 Pa. Change one driving input at a time and confirm the result moves in the direction predicted by the equation; that is a quick way to catch a unit or mode mistake.

How to interpret the result

Interpret the Pressure change within the fluid, geometry, pressure reference, and property values you entered. A numerically plausible answer can still be physically wrong if gauge/absolute pressure, diameter/radius, viscosity type, or unit convention is mismatched, so compare the result with the assumptions as well as the formula.

Limitations and notes

Bernoulli’s ideal form neglects pump/turbine work, frictional head loss, compressibility, and strong unsteadiness unless those effects are added separately. Optional diameter fields can support flow-related values but do not turn the page into a complete continuity/network solver.