Density calculator
Density is mass divided by volume, so any two of the three give the third. Reference values for common materials are listed, which lets you check a result or identify an unknown offcut.
- Mass (g)
- 2,700.000
- Volume (cm³)
- 1,000.000
- In kg/m³
- 2,700.0
- In lb/ft³
- 168.56
- Relative to water
- 2.700
- Floats in water
- No
- Closest common material
- Aluminium
| Material | g/cm³ |
|---|---|
| material:water | 1 |
| material:ice | 0.917 |
| material:aluminium | 2.7 |
| material:steel | 7.85 |
| material:copper | 8.96 |
| material:lead | 11.34 |
| material:gold | 19.32 |
The formula
ρ = m / V, so m = ρV and V = m / ρ. One gram per cubic centimetre equals 1,000 kilograms per cubic metre, and water is almost exactly 1 g/cm³ at 4 °C, which is why relative density is read against it.
Worked example
2,700 g occupying 1,000 cm³ is 2.7 g/cm³ — aluminium. It is 2.7 times denser than water, so it sinks.
How to use it
- 1Measure volume by displacement for an irregular object: submerge it and read the water it pushes aside.
- 2Keep units consistent. Grams with cubic centimetres gives the familiar figures; the conversions to kg/m³ and lb/ft³ are shown alongside.
- 3Use the reference table to sanity-check a result. A metal at 7.8 is steel; at 2.7 it is aluminium.
Questions people ask
Why does ice float?
Water is unusual: it expands as it freezes, so ice is 0.917 g/cm³ against liquid water's 1.0. Almost every other substance is denser as a solid.
Is density the same as specific gravity?
Specific gravity is density relative to water, so it is the same number without units when you work in g/cm³. That is the figure shown as 'relative to water'.
Last reviewed: 2026-10-20