The pressure at depth h below the surface of a liquid of density $\rho$ open to the atmosphere is

The pressure at depth h below the surface of a liquid of density $\mathrm{\rho }$ open to the atmosphere is $\mathrm{P}={\mathrm{P}}_{\mathrm{a}}+\mathrm{\rho gh}$, where P_a is the atmospheric pressure. Thus, pressure P at depth h below the surface of a liquid open to the atmosphere is greater than the atmospheric pressure by an amount $\mathrm{\rho gh}$.