# What are units used to measure gas pressure?

May 1, 2014

Gas Pressure is measured in a variety of units.

Standard Temperature and pressure call for one atmosphere (1 atm) at ${0}^{o} C$ which is 273 K.

According to the wok of Evangelista Torrcelli, at sea level, 1 atm of air pressure will sustain a column of mercury at 760 mm meaning

1 atm = 760 mmHg or 1 atm = 760 torr (torrcellis)

In physics, the measure is completed in units called Pascals where 1 atm of gas is equivalent to 101,325 Pa or 101.3 kPa (kiloPascals).

In the United States where the System International (SI) is still just a fad, we can still find pressure in pounds per square inch or psi.