Volume calculator
Volume and surface area for the five shapes most things actually are. Each one shows the formula it used and the numbers put into it, so you can check the answer rather than trust it. Nothing you type here leaves your browser — it is worked out on your own device, so there is nothing to send and nothing to log.
The cone is the one with a hypotenuse in it
Four of these five are multiplication. The cone's surface area is not: it needs the slant height, which is the distance from the rim to the tip, and that is √r² + h² — a hypotenuse.
Computed the obvious way, that squares before it roots, and for a very wide or very tall cone the square overflows. This page uses the same scaled function as the distance calculator, for exactly the same reason. It is the only place in this page where the arithmetic could have gone wrong, and it is worth saying which one it was.
The volume of a cone is a third of the cylinder that would contain it, which is worth knowing because it is the one formula here people misremember — and the working below writes it out rather than producing a number.
Where to go next
- Triangle area calculator
- Distance between two points
- Circle calculator
- Right-angled triangle — when you know two sides and the angle is ninety degrees.
- Every tool on the site