Volume facts for kids
- This article is about physical object; for meaning from audio field, see loudness.
Volume is a way to measure how much space an object takes up. Think of it as the total amount of room inside something. For example, a big mountain takes up much more space than a small rock. Volume is different from mass, which is how much "stuff" an object has.
When we talk about volume, we usually mean a three-dimensional object. This means it has:
- The length: How long the object is from one end to the other.
- The width: How wide the object is, going sideways from its length.
- The height (or depth): How tall or deep the object is, going up and down.
Every physical object has a volume. Even very thin things, like a sheet of paper, take up some space, even if they seem almost two-dimensional.
Units for Measuring Volume
The main unit for volume in the International System of Units (SI) is the cubic meter. We write this as m3. Imagine a box that is 1 meter long, 1 meter wide, and 1 meter tall – that's one cubic meter of space!
People often use other units for volume to make things easier:
- Litres (L) are common for measuring liquids. A litre is the same as a cubic decimetre. You might see litres on juice cartons or soda bottles.
- Barrels are used for large amounts of liquids, like oil. The exact size of a barrel can change depending on what's inside it.
Some countries still use older units. For example, in the United States, people use units like the gallon, quart, cup, and teaspoon, especially in cooking. The British Empire also used Imperial units like the gallon and fluid ounce.
How to Measure Volume
In mathematics, you can often calculate the volume of simple shapes using formulas:
- For a perfect cube with a side length of c, the volume (V) is c × c × c, or c3.
- For a rectangular box, you multiply its length, width, and height.
- For a sphere (a perfect ball) with a radius of r, the volume is (4/3) π r3.
You can also measure volume in other ways:
- The volume of a gas is usually the same as the volume of its container.
- The volume of a liquid is often measured by pouring it into a container that has measurement marks on its side, like a measuring cup.
- To find the volume of a small solid object, you can put it into a measuring container that already has some liquid in it. The liquid level will rise, and the difference in the liquid level tells you the object's volume. This only works if the object does not dissolve in the liquid.
Related pages
See also
In Spanish: Volumen para niños
