What is volume?
Year 5 estimates volume and capacity. Year 6 calculates the volume of cubes and cuboids in cm³ and m³. Below: what it means, a worked example, the mistake to watch for and an 11+ question.
The answer
Volume is the amount of space a 3D shape takes up, measured in cubes, such as cubic centimetres (cm³).
What it means
For a cube or cuboid, multiply length × width × height. A box 4 cm by 3 cm by 2 cm holds 24 centimetre cubes, so its volume is 24 cm³.
Capacity is how much a container holds. 1 cm³ holds 1 ml, so 1,000 cm³ holds 1 litre.
A worked example
Find the volume of a cuboid 4 cm by 3 cm by 2 cm
- One layer is 4 × 3 = 12 cubes.
- There are 2 layers: 12 × 2 = 24 cm³.
The common mistake
Adding the three lengths, or writing cm² instead of cm³. Volume multiplies three lengths, so it is counted in cubes.
How it comes up in the 11+
A fish tank is 20 cm long, 10 cm wide and 10 cm high. How many litres of water does it hold when full?
Answer: 2 litres
- Volume = 20 × 10 × 10 = 2,000 cm³.
- 1,000 cm³ is 1 litre, so 2,000 cm³ is 2 litres.
Related words and practice
More maths words
Questions parents ask
What is the difference between volume and capacity?
Volume is the space a solid takes up. Capacity is how much a container can hold, usually in ml or litres.
How many cm³ are in a litre?
1,000. A cube 10 cm by 10 cm by 10 cm holds exactly 1 litre.
Knowing the words is half of an 11+ maths question
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