Hydrostatic pressure Calculator

Formula first

Overview

Pressure in a still fluid increases with depth because the fluid above the point has weight. The total pressure equals the reference or surface pressure plus the hydrostatic contribution from the fluid column.

Symbols

Variables

P = Pressure, $P_0$ = Reference Pressure, $\rho$ = Fluid Density, g = Gravitational Acceleration, h = Depth

Apply it well

When To Use

When to use: Use this for fluids at rest when density is nearly constant and depth is measured downward from a reference surface.

Why it matters: Hydrostatic pressure is the basis for tank design, depth gauges, dams, and many pressure measurements in process equipment.

Avoid these traps

Common Mistakes

• Forgetting to include the reference pressure.
• Using horizontal distance instead of vertical depth.

One free problem

Practice Problem

Water has density 1000 kg/$m^3$. If surface pressure is 101325 Pa, g is 9.81 m/$s^2$, and depth is 3.0 m, what is the pressure?

Solve for: pressure

Hint: Add rho g h to the surface pressure.

The full worked solution stays in the interactive walkthrough.

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Related Formulas

References

Sources

1. OpenStax University Physics Volume 1, Pressure in Fluids, accessed 2026-04-09
2. OpenStax University Physics Volume 1, Measuring Pressure, accessed 2026-04-09
3. Munson, Young, Okiishi, Huebsch, and Rothmayer, Fundamentals of Fluid Mechanics, Wiley, 2013
4. NIST CODATA
5. IUPAC Gold Book
6. Wikipedia: Hydrostatic pressure
7. Britannica: Fluid statics
8. IUPAC Gold Book: Continuum hypothesis