Density Calculator (ρ = m/V)
Calculate density, mass, or volume with ρ = m/V, compare against a table of common material densities, and solve for whichever value you're missing.
Typical material densities
| Material | kg/m³ | g/cm³ |
|---|---|---|
| Air (20 °C) | 1.204 | 0.001 |
| Cork | 240 | 0.240 |
| Wood (oak) | 750 | 0.750 |
| Ethanol | 789 | 0.789 |
| Ice | 917 | 0.917 |
| Water (4 °C) | 1000 | 1.000 |
| Concrete | 2400 | 2.400 |
| Glass | 2500 | 2.500 |
| Aluminium | 2700 | 2.700 |
| Steel | 7850 | 7.850 |
| Iron | 7874 | 7.874 |
| Copper | 8960 | 8.960 |
| Lead | 11340 | 11.340 |
| Gold | 19300 | 19.300 |
Density
Density is how much mass is packed into a given volume — it's what makes lead feel heavy and cork feel light even in the same-size lump. It's defined as mass divided by volume.
ρ = m / V · m = ρ · V · V = m / ρ
The SI unit is kilograms per cubic metre (kg/m³), though g/cm³ is common too — and conveniently water is almost exactly 1 g/cm³ (1000 kg/m³), which makes it the natural benchmark. Anything denser than water sinks; anything less dense floats. This calculator solves for density, mass, or volume, and names the closest material from the table.
Worked example
A 2 kg object with a volume of 0.001 m³ (one litre) has a density of 2 / 0.001 = 2000 kg/m³ (2 g/cm³) — roughly that of concrete or glass, and twice as dense as water, so it would sink. Rearranged, a 0.5 m³ block of aluminium (ρ = 2700) has a mass of 2700 × 0.5 = 1350 kg.
Watch your units
The formula needs consistent units — kilograms and cubic metres give kg/m³. A cubic metre is a lot: 1 litre is 0.001 m³ and 1 cm³ is 0.000001 m³, so a small object measured in centimetres has a tiny volume in cubic metres. Thelength converter andmass converter help you get there.
Where a single density figure breaks down
Density is exact arithmetic, but the material figures it is compared against are typical rather than fixed. Alloys vary with composition, timber varies enormously with species and moisture content, and any porous material depends on whether you mean bulk or solid density. Temperature matters too: water is densest at 4 °C and everything expands when heated, so a precise measurement needs a stated temperature. Treat a material match as an identification hint, not a determination.