# What are the units used to measure pressure?

Apr 23, 2018

Pascal, or $P a$, (and a few others- but they are mostly derived from Pascals)

#### Explanation:

Pressure in Pascals is defined as the force exerted over an area in meters squared.

$P = \frac{F}{A}$

So in fundamental SI units 1 Pascal is:

$1 P a = k g \times {m}^{- 1} \times {s}^{-} 2$

So 1 Pascal is the equivalent of a force of 1 Newton acting over an area of 1 meter squared.
However, 1 pascal is a pretty small pressure so we often describe pressure in bar, or atmospheres- which uses Kilo-pascals.

Normal pressure at sea level is approximately 101 kilo-Pascals, or 101 000 Pascal. This is often denoted as a pressure of "1 atmosphere". "1 Bar" on the other hand, is equal to 100 000 Pa.

However, there are many more units for measuring pressure- including psi (pressure per square-inch), mmHg... etc. But when doing physics or chemistry, $P a$ is the unit of pressure you should use.

Hope it helped!