Difference Between NM3 and M3

- May 24, 2019-

NM3 vs M3 

NM3 and M3 are the units that are used in measuring the volume of liquids, solids and gases. M3 is the Meter cube and NM3 is Normal Meter cube. Meter Cube is the volume that is occupied by matter in a cube whose sides measure one meter in length. The measurement of volume plays an important role in every aspect of designing, manufacturing and carrying out experiments. Volume of the matter does not remain constant in all conditions but vary with change of pressure and temperature therefore it is very important to set the standards for the volume. NM3 is the value that a matter whether solid, liquid or gas of a constant mass occupies under normal or standard conditions and M3 is volume that it will occupy at the prevailing conditions of temperature and pressure.


The volume of solids does not vary to a great extend with the change in temperature and pressure but the change is significant in case of liquids and gases. A standard for the particular element or compound therefore is very important so that a product can be designed by comparing the volume changes under normal conditions and the conditions in which product will work. NM3 is the standard value of volume occupied by matter under Normal conditions and that is at 0 degree centigrade or 273 degree K and at 1 atmosphere pressure or 1013.25 mbar.


Meter cube is the volume occupied by the matter at the prevailing pressure and temperature. Volume of liquid and gas changes dramatically with the change in temperature and pressure. Volume is directly proportional to temperature and inversely proportional to pressure so when temperature of the matter is increased keeping pressure constant then volume increases and when pressure is increased keeping temperature constant then volume decreases. So M3 is the meter cube of volume occupied by the matter at given temperature and pressure. This measurement of volume is very important in fluid dynamics and aerodynamics to design proper designs of pipes, nozzles, airplane wings and many other industrial products that have to work in extreme temperature and pressure conditions.

In brief:

• Values of NM3 and M3 vary greatly at different temperature and pressure but are same at Normal Conditions.

• NM3 is a standard value and remains constant for a particular compound but value of M3 changes with different conditions of temperature and pressure.

• NM3 is generally used as reference and is rarely of importance in working conditions but M3 has great importance in working conditions.