Calculate density, mass, or volume using ρ = m/V — with a float/sink comparison relative to water density.
How it works
- Enter two variables from Mass, Volume, or Density.
- Keep the variable you want to solve for blank.
- Review the calculated result along with a comparison of buoyancy to water.
Frequently asked questions
What are common material densities?
Water: 1,000 kg/m³. Aluminum: 2,700. Steel: 7,850. Lead: 11,340. Air: ~1.2. Gold: 19,300.
Why do ships float if steel sinks?
A steel ship is mostly air inside. The average density of the ship (steel + air + cargo) is less than water, so it floats.
How do I convert units?
This calculator uses SI (kg and m³). Convert: 1 g/cm³ = 1,000 kg/m³. 1 lb/ft³ = 16.02 kg/m³.