Density Calculator

Solve density, mass or volume using density = mass ÷ volume.

g
cm³
Density
Mass
Volume
Density in kg/m³
In water

1 cm³ equals 1 ml. Water is about 1 g/cm³ (1,000 kg/m³) — the dividing line between floating and sinking.

Mass packed into space

Density measures how concentrated matter is — the mass contained in a unit of volume. It explains why a small lead ball feels heavy while a big foam block feels like nothing at all.

density = mass ÷ volume · mass = density × volume · volume = mass ÷ density

Because the three quantities are tied by one equation, knowing any two gives the third. Pick what you want to find and the calculator rearranges the formula for you.

Worked example

100 g occupying 50 cm³ has a density of 2 g/cm³ — that is 2,000 kg/m³, twice the density of water, so it would sink.

Density in the world

Density decides what floats, helps identify materials, and matters everywhere from ship design to cooking. Comparing a material’s density to water’s — its specific gravity — is a quick way to predict whether it will sink or swim.

Worth remembering

  • Water ≈ 1 g/cm³. The handy reference point for floating.
  • 1 cm³ = 1 ml. Volume in cooking and chemistry lines up neatly.
  • ×1,000 for SI. g/cm³ to kg/m³ is just a factor of a thousand.

Frequently asked questions

What is density?
How much mass is packed into a given volume: density = mass ÷ volume. A dense material has a lot of mass in a small space, like lead; a light one has little, like cork.
What units does it use?
Here, mass in grams and volume in cubic centimetres (equal to millilitres), giving density in g/cm³. Multiply by 1,000 to get kg/m³, the SI unit.
Will it float or sink in water?
Water is about 1 g/cm³. Anything less dense floats; anything denser sinks. The calculator notes which side of that line your result falls on.
Can I solve for mass or volume?
Yes. Choose what to find, and enter the other two. The same formula rearranges to mass = density × volume, or volume = mass ÷ density.