Area & Volume Calculator

How to use the area & volume calculator

1. Fill in the fields — they start with a worked example.
2. Read the answer, and the arithmetic shown beneath it.
3. Copy the results, or adjust the inputs to compare scenarios.

About this tool

One shape at a time, with the formula printed beside the answer so it can be checked rather than trusted.

Units are whatever you enter — put in metres and the area is square metres, the volume cubic metres. The only rule is consistency: mixing centimetres and metres in one shape is the usual source of an answer that is out by a factor of ten thousand.

Triangle area uses Heron's formula, which needs only the three sides and reports honestly when those lengths cannot form a triangle at all.

Common uses

• Working out floor area for materials.
• Calculating the volume of a tank or container.
• Checking a triangle's area from its three sides.

Frequently asked questions

What units does it use?

Whichever you enter. Areas come out squared and volumes cubed in the same unit — just keep every measurement in one unit.

Why does my triangle say it is impossible?

Because the two shorter sides do not add up to more than the longest. No triangle can be formed from those lengths.