Volume is defined as the amount of three dimensional space occupied by a substance, regardless of its state, i.e. solid, liquid or gas. It is a common misconception that only solids posses volume and the other two states of matter, liquid and gas, do not. Also, it is not necessary for a substance to be in a container to have volume. The standard international unit of volume is cubic meter, but cubic centimetres, litre and millilitre are also used to describe the volume of a substance. Volume is calculated by multiplying the length, width and height of the substance.
Volume = V = (Length) x (Width) x (Height).
Capacity refers to the ability of a container to hold or absorb something. Capacity may have similarities with volume, but it defines how much of a substance (solid, liquid, or gas) can fit in a space. Substances have volume, while containers have a capacity, which is used to denote how much they can hold. For example a jug, glass, cup or a cotton ball can have capacity but a solid steel block or a solid metal ball can’t. Capacity is measured in terms of litres, millilitres, gallons etc. Capacity is also calculated by multiplying the length, width and height of the object.
Capacity = C = (Length) x (Width) x (Height)