Density Calculator

Calculate density, mass or volume with the formula ρ = m ÷ V. Fill in two of the three fields and leave the third at 0, and the calculator works out the rest.

Density
1 kg/liter
Calculated from mass and volume
In kg/m³
1,000 kg/m³
Mass
1 kg

How to use the density calculator

  1. Enter the two values you know: mass, volume or density.
  2. Leave the field you don't know at 0 — the calculator automatically works out this value.
  3. If you fill in all three fields, the calculator instead checks whether they actually match.

The formula for density

ρ = m ÷ V

The density (ρ) of a substance tells you how much mass (m) is packed into a given volume (V). Ordinary water has a density of 1 kg/liter (equivalent to 1,000 kg/m³), and is often used as a natural reference point for other substances.

Ice has a slightly lower density than liquid water (about 0.92 kg/liter), which is exactly why ice floats on water instead of sinking — a substance with lower density than the liquid it's in will float.

Frequently asked questions

Why does ice float on water?

Ice has a lower density than liquid water (about 0.92 kg/liter versus 1.0 kg/liter), because water molecules arrange into a more open lattice when water freezes. A substance with lower density than the liquid around it will always float, which is why ice cubes and icebergs float on water.

What's the density of ordinary water?

Pure water at room temperature has a density of about 1 kg/liter, equivalent to 1,000 kg/m³. This value is often used as a reference when comparing the density of other substances and materials.

How do I convert between kg/liter and kg/m³?

One liter equals 0.001 m³, so you multiply the density in kg/liter by 1,000 to get the density in kg/m³. For example, 1 kg/liter becomes 1,000 kg/m³, the common SI unit for density.