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Cube Calculator

Volume, surface area and the space diagonal.

Work out Cube. Volume, surface area and the space diagonal. Shows the working, not just the answer.

Written and maintained by Mohit PatelLast checked August 4, 2026How we build these

Volume (units³)

27

Surface area 54 units²

Volume27 units³
Surface area54 units²
Lateral (side) area36 units²
Base area9 units²
If units are cm0.027 litres
Face diagonal4.2426 units
Space diagonal5.1962 units

Volume is s³ and surface area 6s², since a cube has six identical faces. The space diagonal — corner to opposite corner through the middle — is s√3, which is what limits the longest object that fits inside: 5.1962 units here, not the 3 you might expect from the side alone.

How the Cube Calculator works

Volume is s³ and surface area 6s², since a cube has six identical faces. The figure people forget is the space diagonal — corner to opposite corner through the middle, at s√3 — which is what actually limits the longest object that will fit inside.

Also known as: volume of a cube · surface area of a cube · cube volume formula · space diagonal of a cube

Frequently asked questions

How do I find the volume of a cube?

Cube the side length. A side of 3 gives 27 cubic units.

What is the surface area of a cube?

Six times the side squared, because there are six identical square faces. A side of 3 gives 54 square units.

What is the space diagonal?

The longest line inside the cube, from one corner to the opposite one through the centre. It is s√3, so a cube of side 3 has a space diagonal of 5.196 — noticeably longer than the side or the face diagonal.

How many litres is my cube?

If you measure in centimetres, divide the volume by 1,000. A 10 cm cube is exactly one litre, which is how the litre is defined.

Put this calculator on your own site

Free to use, on any site, commercial or not. Paste this where you want it to appear. It is a plain iframe, so it works in WordPress, Squarespace, Wix, Webflow, Ghost and anything else that accepts HTML.

The one-line version
<iframe src="https://www.thecalclibrary.com/embed/cube-calculator" width="100%" height="640" style="border:1px solid #e2e8f0;border-radius:12px" loading="lazy" title="Cube Calculator"></iframe>

The only condition is that the credit line stays visible. It sits inside the frame, so you do not have to do anything to keep it.

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