Hydrostatic Pressure Calculator
This hydrostatic pressure calculator turns liquid and depth into p = ρ·g·h. Example: at 10 m of water depth the hydrostatic pressure is about 0.98 bar, and with the air pressure at the surface roughly 2 bar.
Example: What do you want to calculate: Pressure at a depth · Liquid: Fresh water (998 kg/m³) · Depth below the surface 10 m → Result: Hydrostatic pressure: 0.9787 bar (97,870 Pa). Source: Wikipedia – Schweredruck (hydrostatischer Druck). Updated: .
How it is calculated
Hydrostatic pressure is the pressure that the weight of a liquid column creates at a given depth: p = ρ·g·h. Here ρ is the density, g the gravitational acceleration (9.80665 m/s²) and h the depth below the surface. It grows linearly with depth and does not depend on the shape of the container.
How it is calculated
In 10 m of fresh water with ρ = 998 kg/m³, p = 998·9.80665·10 ≈ 97,870 Pa, about 0.98 bar. As a rule of thumb, pressure in water rises by roughly 1 bar every 10 m. At 30 m in seawater (1025 kg/m³) the hydrostatic pressure is about 3.02 bar. Divers and gauges usually show the absolute pressure, which adds the air pressure of about 1.013 bar at the surface: at 30 m in seawater that is a little over 4 bar.
Depth and force
In the second mode you find the depth from a measured pressure, for example for probes or depth gauges. If you enter an area in the pressure mode you also get the force F = p·A, for instance on a porthole, a lock gate or a diving mask.
- Mercury is 13.6 times denser than water: a 760 mm column matches standard pressure.
- Hydrostatic pressure acts in all directions, not only downward.
- The densities are typical values; warm or low-salinity water differs slightly.
Frequently asked questions
How much pressure is there at 10 m of water depth?
The hydrostatic pressure is about 0.98 bar. Together with the air pressure at the surface the absolute pressure is roughly 2 bar.
What is the difference between hydrostatic and absolute pressure?
Hydrostatic pressure comes from the liquid column alone. Absolute pressure adds the pressure at the surface, usually the air pressure of about 1.013 bar.
Why does hydrostatic pressure not depend on the container shape?
Only the vertical height of liquid above the point matters, not the amount. A narrow and a wide container therefore give the same pressure at the bottom at the same fill height.
Sources and legal basis
- Wikipedia – Schweredruck (hydrostatischer Druck)
- Wikipedia – Hydrostatic pressure
- Wikipedia – Normfallbeschleunigung (g_n = 9,80665 m/s²)
As of: · Editorial policy
Related tools
- Bar to psi converterConvert bar to psi and back: 1 bar = 14.504 psi. Also pascal, kPa, atm, mmHg and water column – with the working, a chart and a note on psig vs psia.
- Density calculator: density, mass and volumeCalculate density, mass or volume with ρ = m/V – step-by-step, with unit conversion from g/cm³ to kg/m³ and lb/ft³ and densities of water, metals and plastics.
- Buoyancy CalculatorBuoyancy calculator after Archimedes: buoyant force, float or sink, submerged share and payload, plus the lift of helium and hot-air balloons.
- Force CalculatorForce calculator in newtons: from mass and acceleration, weight, pressure and area, spring constant or the lever law – with unit conversion and working.
- Pipe flow rate calculatorPipe flow rate calculator: from diameter and velocity or the other way round, with Reynolds number and pressure drop for water pipes. With the working shown.
- Horizontal Tank Volume CalculatorHorizontal tank volume calculator for cylindrical tanks: liquid volume from the dipstick depth, or the depth from litres, with fill level. Free.
- Online CalculatorCalculator online, free and instant: type or tap and see the answer as you go – order of operations, brackets, percent, square root, steps and a history list.
- Bar to kPa converterBar to kPa: multiply by 100, so 2.2 bar = 220 kPa. Convert bar to kilopascals or kPa to bar, with psi, atmospheres, megapascals and a pressure chart.
- Hardy Weinberg calculator for allele and genotype frequenciesHardy Weinberg calculator: allele frequencies p and q from genotype counts, from the share of recessive individuals (q²) or from p, plus p², 2pq and q².