Pressure Conversion – Atm to kPa

Mercury barometers used to measure air pressure. Credit: Edal Anton Lefterov/Creative Commons

Pressure is a measurement of force per unit area. Atmospheres (atm) is a common unit when working with gasses and the pascal is the SI unit of pressure equal to one newton per square meter (N/m2). Pascal represents a very small pressure so the larger kilopascal (kPa) is used more often when working with larger pressures. This example problem shows how to convert atm to kPa units.

Example Problem:
The pressure at sea level is generally considered to be 1 atm.  Pressure increases the deeper you dive in the ocean by roughly 1 atm every 10 meters. At a depth of 50 meters the pressure will be 5 atm. What is this pressure in kPa?

The relationship between atm and Pa is:

1 atm = 1.013 x 105 Pa

The other relationship needed is the number of pascals in a kilopascals.

1 kPa = 1000 Pa

Multiply 5 atm by these conversion factors to calculate kPa.

atm to kPa conversion math
? kPa = 506.5 kPa

The pressure 50 meters underwater is equal to 506.5 kPa.

For further explanation of using conversion factors in this way, check out How to Convert Units and the Ladder Method.