Water pressure, also known as hydrostatic pressure, when dealing with static or non-moving fluid, can be calculated relatively easily. The type of simple calculation that is shown below can even be applied to oceanic situations as it has been experimentally shown that the waves and movement of the water have very little effect on the water pressure.
Determine at what depth you wish to calculate the water hydrostatic pressure. Express this value in meters.
Using a barometer, obtain the atmospheric pressure at the surface of the water. Express this value in kg/ms². See "Resources" below for an easy and quick conversion factor table.
Use what is generally accepted as the standard values for water density and the earth's gravitational acceleration: water density = 1000kg/m³ earth's gravitational acceleration = 9.81m/s²
Substitute the values obtained in Steps 1 through 4 into the following equation. Calculate when done.
P = a+l_g_h where P = water pressure (hydrostatic) a = atmospheric pressure at water's surface l = water density g = gravitational acceleration.
Use the result as the calculated hydrostatic pressure for the depth used in the equation. Multiply this number by .014 to express this pressure in pounds per square inch units.
Each cubic foot of water weighs about 283 Kilogram.