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Fluid Mechanics

Hydrostatic Pressure Calculator

Hydrostatic pressure is the pressure exerted by a static column of fluid due to gravity. It depends on the fluid density, the height of the liquid column, and the gravitational acceleration. This calculator solves for pressure, height, or density when the other two are known. You must supply the fluid density — no fluid property lookup is performed.

TypeInteractive calculator — separate from unit conversions

Calculator

User-supplied — no lookup

m/s²

Standard gravity (visible, editable)

Result
Pressure98.0665 kPa
Pressure (Pa)98066.5 Pa

Formulas

Pressure from height
P = ρ × g × h
Height from pressure
h = P / (ρ × g)
Density from pressure and height
ρ = P / (g × h)

Diagram

Hydrostatic Pressure: P = ρghfree surfaceh (height)P = ρ × g × hρ (density)g (gravity)uniform ρ

Worked example

A column of water (ρ = 1000 kg/m³) is 10 m high. Gravity = 9.80665 m/s². What is the pressure at the base?

  1. 01P = ρ × g × h
  2. 02P = 1000 × 9.80665 × 10
  3. 03P = 98,066.5 Pa
  4. 04P = 98.0665 kPa
Result

The hydrostatic pressure at the base of a 10 m water column is 98,066.5 Pa (98.0665 kPa).

FAQ

Is this a tank or vessel design calculator?
No. This calculator determines hydrostatic pressure from a static liquid column. Tank wall stress, vessel design pressure, and structural calculations are not included.
Does this look up fluid density?
No. You must supply the fluid density directly. No fluid property lookup or database is used.
Does this assume uniform density?
Yes. The formula P = ρgh assumes constant density throughout the column. For stratified fluids or columns with significant temperature gradients, this approximation may not be accurate.
Is this gauge pressure or absolute pressure?
This calculates gauge pressure from the liquid column only. To obtain absolute pressure, add the atmospheric pressure at the liquid surface.