# Hydrostatic Pressure Calculator

URL: https://speedycalculator.com/calculators/physics/hydrostatic-pressure/
Last updated: 2026-10-30

> The hydrostatic pressure calculator finds the gauge and absolute pressure at a depth in a liquid from its density, the depth, gravity and the pressure at the surface.

## Inputs

- Liquid
- Liquid density (kg/m³, g/cm³, g/mL, lb/ft³, lb/in³)
- Depth h (m, cm, mm, km, in, ft, yd, mi)
- Gravitational acceleration g (m/s², ft/s², g, cm/s²)
- Surface pressure p₀ (kPa, Pa, bar, psi, atm, MPa)

## Results

- Gauge pressure
- Absolute pressure
- In atmospheres (absolute)

## Formula

```
p = ρ·g·h + p₀
```

## Explanation

Pressure in a liquid increases steadily with depth because of the weight of the liquid above. In water it rises by about 1 atmosphere every 10 metres – which is why divers must equalise and why dams are thicker at the bottom.

### How to use the Hydrostatic Pressure Calculator

- **Liquid**
- **Liquid density**
- **Depth h**
- **Gravitational acceleration g**
- **Surface pressure p₀**

Results update as you type, every field has its own unit menu, and everything is calculated in your browser.

### How it works

Choose the liquid, enter the depth, gravity and the surface pressure (usually atmospheric).

### Inputs explained

FieldWhat to enterLiquidChoose one: Fresh water (20 °C), Seawater, Air (sea level, 15 °C), Ethanol …Liquid densityUnits: kg/m³, g/cm³, g/mL, lb/ft³, lb/in³Depth hUnits: m, cm, mm, km, in, ft …Gravitational acceleration gUnits: m/s², ft/s², g, cm/s²Surface pressure p₀Units: kPa, Pa, bar, psi, atm, MPa

### Example values

How the main result changes when **Liquid density** changes and everything else stays at the example values above:

Liquid density (kg/m³)Absolute pressure (kPa)500199.215750199.2151,000199.2151,250199.2151,500199.2152,000199.215

## Worked example

Inputs — Liquid: Fresh water (20 °C); Depth h: 10 m; Gravitational acceleration g: 9.80665 m/s²; Surface pressure p₀: 101.325 kPa.

Results — Gauge pressure = 97.88998 kPa; **Absolute pressure = 199.21498 kPa**; In atmospheres (absolute) = 1.9661 atm.

## Key terms

- **Hydrostatic pressure**: Pressure due to the weight of a fluid at rest.

## FAQ

**How fast does water pressure rise?**
About 9.8 kPa per metre – 1 atm every 10 m.

**Does the container shape matter?**
No – only the depth (the hydrostatic paradox).

**What is gauge pressure?**
Pressure above atmospheric.

**Why are dams thicker at the base?**
Water pressure is greatest at the bottom.


## Sources

- [OpenStax – University Physics Volume 1](https://openstax.org/details/books/university-physics-volume-1)
- [The Engineering ToolBox](https://www.engineeringtoolbox.com/)