Home  ›  Learning Centre  ›  Maths  ›  Measurement  ›  Volume of Cuboids
11+ Maths Guide · Year 5–6 · Free lesson

Volume of Cuboids

Volume is counting cubes: one layer of length × width, stacked height times. This lesson builds the l × w × h formula from that picture and fixes the cm²-vs-cm³ confusion for good.

ME13Volume of Cuboids
Layers of centimetre cubes.
Volume of a cuboid = length × width × height — layers of unit cubes.
How many 1 cm cubes fill the box?
length 5 cmheight 4 cmwidth 3 cm
5 × 3 × 4 = 60 cm³
One layer = 5 × 3 = 15 cubes; 4 layers = 60 cubes.
1

Learn the 3-Step Method

1Find one layer.

The bottom layer holds length × width cubes: 5 × 3 = 15.

5 × 3 = 15

2Count the layers.

The height says how many layers stack up: 4.

4 layers

3Multiply.

15 × 4 = 60 cubes → 60 cm³.

15 × 4 = 60
💡 Key IdeaVolume is measured in cubic units — cm³, m³ — because we're counting cubes, not squares.
2

Worked Example

A toy box is 40 cm long, 30 cm wide and 20 cm tall. Find its volume.

Layer
40 × 30 = 1200
Stack
1200 × 20 = 24000
✓ Answer
24 000 cm³
3

Watch Out! Common Mistakes

Only multiplying two sides.
V = 5 × 3 = 15 cm³ ✕

Wrong! That’s one layer (area). Multiply by the height too: 5 × 3 × 4 = 60 cm³.

Wrong unit.
V = 60 cm² ✕

Wrong! Volume counts cubes: cm³. (cm² is area — flat squares.)

Order worries.
3 × 5 × 4 vs 5 × 4 × 3

Relax! Multiplication order doesn’t matter — all orders give 60. Pick the easiest pairing.

📄 Free printable: Download the Volume of Cuboids cheat sheet (PDF) — keep it by your child's desk.

Quick summary

Frequently asked questions

What is the formula for the volume of a cuboid?

Length × width × height. A 5 × 3 × 4 cm box holds 60 cm³.

Why is volume measured in cm³?

Because it counts how many 1 cm × 1 cm × 1 cm cubes fit inside — cubes, not flat squares.

When do children learn volume?

Counting cubes starts in Year 5; using l × w × h (including cm³ and m³) is a Year 6 objective in England.

← Previous lesson
ME12 Compound Shapes
All lessons
Measurement Hub
Next lesson →
ME14 Telling the Time
🛡️ Curriculum aligned⭐ Builds confidence💜 Made for 9–13 year olds
© MindBlaze. Free to read, share and link to. Learning Centre