Question

How do you calculate density of matter?

Answer 1

Density is defined as mass per volume-unit.

So you first need to know the mass of an object. You can do this by weighing it.

Then you want to know the volume . If your object is of a regular form, e.g. a block, you can calculate length x width x height. In other cases you can submerge the object in water (in a graduated cylinder) and note the difference in water level.

After that, it's: density=mass/volume, or `rho=m/V`

Extra:
Officially, density is expressed in the unit `kg//m^3`, but as this would lead to high figures (water has `rho=1000 kg//m^3`), often the density is expressed in `kg//dm^3 or g//cm^3` (they have the same numerical value). So mercury would have an official density of `13.6*10^3 kg//m^3` but usually this is just abbreviated to `13.6` (this is called relative density, water being 1)