# Difference Between Volume and Capacity

Volume and capacity are usually considered as interchangeable terms but they are not the same. There is a correlation between volume and capacity but they are two different mathematical terms. Whenever a container and the substance it contains come into discussion, volume and capacity are the terms used to describe the amount present in the container. This is the reason most of people assume that they are one and the same, but actually they are not. There is a slight difference between the two which can only be explained through an example. The best example to illustrate the concept of volume and capacity is that of a water tank. If the water tank can hold maximum 12 gallons of water, we will say the capacity of the tank is 12 gallons. However, the volume is the actual amount of water currently present in the tank. If you have poured 5 gallons of water in the empty tank, you cannot say the volume of the water is 5 gallons. For the volume, you will need to find the depth (height) of the water and multiply it with the length and width of the tank. Moreover, both water and the tank have volume but only a container has capacity.

### Instructions

• 1

Volume

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).

• 2

Capacity

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)

• 