Surface Area of a Cube Calculator

Published on: July 14, 2024

Final Answer: Free • Full Steps: Plus

This Surface Area of a Cube Calculator helps you find the total area of all 6 faces of a cube when the side length is known. It uses the formula SA = 6a², where a is the side length and the answer is written in square units. First square the side length, then multiply by 6 to get the surface area. It is a simple way to check answers, understand the cube surface area formula, and practise basic geometry step by step.

In the diagram, each edge is labeled a.

Step-by-step method

Identify what is given.
Write the formula.
Substitute the value and calculate the surface area.

Formula:

\(SA = 6a^{2}\)

Example 1:

\(a = 5\)

Step 1 - Identify what is given.

In this problem: The given edge length is \(a = 5\).

\(a = 5\)

Step 2 - Write the formula.

In this problem: Use the cube surface area formula: \(SA = 6a^{2}\).

\(SA = 6a^{2}\)

Step 3 - Substitute the value and calculate the surface area.

In this problem: Substitute \(a = 5\): \(SA = 6 \times 5^{2} = 150\).

\(SA = 6 \times 5^{2} = 150\)

Final answer:

\(SA = 150\)

Example 2:

\(a = 3.5\)

Step 1 - Identify what is given.

In this problem: The given edge length is \(a = 3.5\).

\(a = 3.5\)

Step 2 - Write the formula.

In this problem: Use the cube surface area formula: \(SA = 6a^{2}\).

\(SA = 6a^{2}\)

Step 3 - Substitute the value and calculate the surface area.

In this problem: Substitute \(a = 3.5\): \(SA = 6 \times 3.5^{2} = 73.5\).

\(SA = 6 \times 3.5^{2} = 73.5\)

Final answer:

\(SA = 73.5\)