Pressure and Archimedes' principle

Two pillars of hydrostatics. Hydrostatic pressure increases with depth:

$p=\rho\, g\, h$

where $\rho$ is the density of the fluid, $g=9.81\ \tfrac{\text{m}}{\text{s}^2}$, and $h$ — the depth. Importantly, it does not depend on the shape of the container (the hydrostatic paradox).

Archimedes' principle describes the buoyant force acting on a submerged body:

$F_{wyporu}=\rho\, g\, V$

equal to the weight of the displaced fluid ($V$ — volume of the submerged part). A body floats when the buoyancy balances its weight. The calculator has presets for the density of common fluids.