Surface area of a cube
Understanding surface area is essential for product designers and engineers to calculate exactly how much material is needed to manufacture packaging boxes. It is also a vital skill for painters and decorators to estimate the amount of paint required to cover the walls of a room. Jump to the questions
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Worksheet preview and key skills
Worksheet preview
Practise surface area of a cube with this self-marking maths worksheet.
The interactive worksheet below generates questions, gives instant feedback, and lets students record their score.
What you’ll practise
- Finding the area of one square face.
- Recognising that a cube has 6 equal faces.
- Multiplying the face area by 6.
- Giving the answer in square units.
Use the interactive worksheet below, or read the Topic guide for the method and worked example.
Calculate the surface area, face area, or side length of a cube.
Topic guide
What this worksheet practises
This worksheet provides practice on calculating the total surface area of a cube. Surface area is the total area of all the outside faces of a 3D shape, like wrapping paper covering a box. A cube is the simplest 3D shape because every single face is exactly the same.
Key method
A cube is made up of exactly 6 identical square faces.
- Identify the length of one side of the cube. (In a cube, the length, width, and height are all the same number).
- Calculate the area of just one of the square faces. (Area of a square = base × height).
- Because a cube has 6 identical faces, multiply the area of that single face by 6 to get the total surface area.
- Write the units correctly. Because it is an area, the units must be squared (e.g. cm², m²).
Worked example
Calculate the surface area of a cube with a side length of 5cm.
Step 1: Find the area of one face.
The face is a square with sides 5cm by 5cm.
Area = 5 × 5 = 25 cm².
Step 2: Multiply by 6 because there are 6 identical faces.
25 × 6 = 150.
The total surface area is 150 cm².
Common mistakes to avoid
The most common mistake is calculating the volume instead of the surface area. A student might see a cube with side length 5 and automatically do 5 × 5 × 5 = 125. This tells you how much space is inside the cube, not the area of its outside faces. Always read the question carefully.
Things to remember
Sometimes a question will tell you the total surface area and ask you to work backwards to find the side length. If the total surface area is 54 cm², you would divide by 6 first (54 ÷ 6 = 9 cm² per face), and then square root that number to find the side length (√9 = 3cm side length).