Because volume is what fills capacity.
volume and capacity is math
Capacity is the volume of the container.
Capacity is potential volume; that is the volume that you can put into a container.
Area is the space in which a thing takes up. Volume is the capacity in which a thing can or is holding
Both are units of volume or capacity, and have the dimensions of (length)3.
Its capacity or volume - measured in the same units.Its capacity or volume - measured in the same units.Its capacity or volume - measured in the same units.Its capacity or volume - measured in the same units.
capacity
Capacity in the sense of volume is measured in cubic metres, although litres (0.001m3) are common. Electrical capacitance is measured in farads.
CC is a VOLUME, -the capacity of that engine. It has NO relationship whatever to horsepower, which is totally different
vital capacity
There is no metric unit of capacity or volume that is equal to 1000 millimeters. This is because millimeters is length, and it has no relevance to capacity and/or volume.
Mass is how much matter there is in something. Capacity is like volume.