Missing Dimension From Cuboid Volume

Missing Dimension in a Cuboid

A cuboid’s volume is found by multiplying its three dimensions:

Volume = length × width × height

If one dimension is missing, the idea is to work backward from the volume.

Method

1. Write the volume formula for the cuboid.
2. Substitute the two known dimensions and the given volume.
3. Solve for the missing dimension by dividing the volume by the product of the known dimensions.
4. Simplify your answer if needed.

Example structure

If the volume is given and two sides are known, set up:

missing dimension = volume ÷ (known length × known width)

or the matching division for whichever side is missing.

Check your result

Multiply the three dimensions together again. If the product matches the original volume, your missing dimension is correct.

Useful tips

• Make sure all measurements use the same unit.
• If the answer is a fraction or a decimal, leave it in simplified form.
• If the numbers are large, calculate the product of the known sides first, then divide.

This method works for any cuboid missing one side: find the product of the known dimensions, divide the volume by that product, and verify by multiplying back.