Density Calculator

1. Enter any two of mass, volume and density.
2. Leave the one you want to find blank.
3. Read the result.
4. See which value was solved for and the formula used.

Here is what each result means:

Density is how much mass is packed into a given volume. It is defined as mass divided by volume, so a heavy object in a small space is dense, while a light object in a large space is not. Water, for example, has a density of about 1 gram per cubic centimeter.

Density explains why some things float and others sink: an object less dense than the fluid around it floats. It is a fixed property of a material at a given temperature, so it helps identify substances and is central to physics, chemistry and engineering. This calculator links density, mass and volume so you can find any one from the other two.

Two objects can have the same mass yet very different densities if one takes up far more space. A kilogram of feathers and a kilogram of lead weigh the same, but the lead is far denser and fills a much smaller volume. Density captures exactly that idea of how tightly matter is packed, independent of how much of it there is.

It rearranges one simple relation to solve for whichever value you leave blank.

1. For density, divide mass by volume.
2. For mass, multiply density by volume.
3. For volume, divide mass by density.

Volume itself often comes from a shape; the volume calculator finds it for spheres, cylinders and boxes.

An object has a mass of 200 grams and a volume of 25 cubic centimeters.

Calculation: rho = 200 / 25 = 8 grams per cubic centimeter. That is denser than water, so it would sink. To find the mass of 25 cubic centimeters at this density, multiply back: 8 times 25 is 200 grams.

Density is a fingerprint of a material, in grams per cubic centimeter.

Anything less dense than water, below 1, floats on it; anything denser sinks. This is exactly why a steel ship floats even though steel is far denser than water: its hull encloses enough air that the average density of the whole ship drops below that of water, so it stays up.

These are often confused but describe different things.

Density uses mass, not weight, so it does not change with gravity. The same object has the same density on Earth or the Moon.

The Material

Each substance has its own density, which is why density helps identify what something is made of.

Temperature

Most materials expand when heated, spreading the same mass over more volume, so density falls a little.

State and Packing

A gas is far less dense than the same substance as a liquid or solid, because its particles are spread out.

Physics and Chemistry

Find a material density, or the mass or volume from it.

Identifying Materials

Compare a measured density with known values to tell substances apart.

Buoyancy

Check whether something will float by comparing its density with the fluid.

1. Mixing Up Units

Density depends on the units of mass and volume. Keep them consistent, or convert first.

2. Confusing Mass and Weight

Density uses mass. Weight changes with gravity, but density does not.

3. Dividing the Wrong Way

Density is mass over volume, not volume over mass.

4. Using Volume of Zero

You cannot find density from a zero volume, since that divides by zero.

5. Ignoring Temperature

For precise work, remember density shifts slightly with temperature.

The relation is exact; only the displayed decimals are rounded.

Density is mass divided by volume, how much matter is packed into a space. Water is about 1 gram per cubic centimeter. A denser object has more mass in the same volume.

Divide the mass by the volume. A 200 gram object filling 25 cubic centimeters has a density of 200 over 25, which is 8 grams per cubic centimeter.

Multiply the density by the volume. This tool does it when you leave the mass field blank and enter density and volume.

Divide the mass by the density. Leave the volume field blank and enter mass and density, and the calculator solves for it.

Whatever units you use for mass and volume, such as grams per cubic centimeter or kilograms per liter. Keep them consistent for a correct result.

An object floats when it is less dense than the fluid around it. Less dense than water, below 1 gram per cubic centimeter, means it floats on water.

No. Density uses mass, the amount of matter, not weight, the pull of gravity. Density stays the same wherever you are, while weight changes with gravity.

Slightly. Most materials expand when heated, spreading the same mass over more volume, so their density falls a little as temperature rises.

No. The calculation runs in your browser and nothing you enter is stored or sent anywhere, unless you choose Save, which keeps the result only on this device.

• Density (Wikipedia).
• Density explained (Maths Is Fun).
• Buoyancy (Wikipedia).