How to calculate pressure in a liquid?

Divide the liquid's mass by its volume. for instance if you have 310 pounds of water in a cubic foot container

310/5=62 pounds per cubic foot

multiply your answer by the liquid's depth. if the liquid is 2 feet deep:

62*2=124

multiply your answer by 32 a constant that reprensents gravitational acceleration:

124*32=4,288

its an example but follow the steps

Pressure attitude can be determined by dialing your kollsman window to 29.92" or 1013mb the altitude displayed will be pressure altitude. Or if you want to use a mathematical equation to calculate pressure it is: 29.92-current baro.=x then take x*1000+Current field elevation = pressure altitude.