Where P is the hydrostatic pressure measured in SI in pascals (Pa), ρ is the fluid density measured in kilograms per cubic meter (kg/m³), P 0 the external pressure measured in Pa, which is usually the atmospheric pressure ( P 0 = 101325 Pa), g is the gravitational acceleration measured in meters per second squared (m/s²), and h is the depth of the fluid measured in meters (m).
The hydrostatic pressure is defined by the following formula called the hydrostatic equation, which is used in this calculator: It increases in proportion to the depth of the fluid because as a body goes deeper, there will be more liquid above it, with greater weight acting on the same surface (more about pressure in our pressure calculator and pressure unit converter). Hydrostatic pressure is the pressure exerted by a fluid at equilibrium due to the force of gravity at any given point within the fluid. Hydrostatics explains many phenomena of everyday life, for example, why things can float on water or sink in it and why still water surface is level and perpendicular to the direction of gravity. Hydrostatics has many applications in meteorology, medicine (studying pressure in blood vessels), biology, and engineering, for example in the design of equipment for using, transporting fluids, or the design of dams.
Unlike hydrodynamics, which deals with the motion of fluids and the forces acting on solid bodies in fluids in motion, hydrostatics studies mechanical properties and behavior of fluids at rest in stable equilibrium and specifically deals with the pressure exerted by non-compressible fluids on immersed bodies. Hydrostatics is a branch of physics that studies the equilibrium of fluids, particularly when it is affected by the gravitational field.