Surface area of a cube

Definition: The number of square units that will exactly cover the surface of a cube
Try this Drag the slider to resize the cube. The surface area is calculated as you drag. Also rotate the cube by dragging it.

How to find the surface area of a cube

Recall that a cube has all edges the same length (See Cube definition). This means that each of the cube's six faces is a square. The total surface area is therefore six times the area of one face.

Or as a formula:

Where s is the length of any edge of the cube.

If you know the surface area

If you already know the area, you can find the edge length by rearranging the formula above: where a is the surface area.


Remember that the length of an edge and the surface area will be in similar units. So if the edge length is in miles, then the surface area will be in square miles, and so on.


Side clear
Volume clear
Surface area clear
Face diagonal clear
Space diagonal clear

Use the calculator on the right to calculate the properties of a cube.

Enter any one value and the others will be calculated. For example, enter the side length and the volume will be calculated.

Similarly, if you enter the surface area, the side length needed to get that area will be calculated.

Things to try

  • Check the "explode" box. Rotate the cube by dragging it to see more clearly that the cube has six identical square faces
  • In the figure above, drag the slider to resize the cube. Note how the surface area is recalculated.
  • Click on "hide details". Resize the cube with the slider. Calculate the surface area, then click "show details" to check your answer.

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