Density Calculator
Find density, mass or volume with ρ = m ÷ V, convert between g/cm³ and kg/m³, and match your answer against known substances.
ρ = m ÷ V
Solve for
ρ
Density
g/cm³
3 sig figs: 2.70
≡
Same value in
2.7 g/mL · 2,700 g/L · 168.6 lb/ft³
- Rearrange: ρ = m ÷ V
- Substitute: m = 54.0 g, V = 20.0 cm³ (converted to SI units first).
- Result: ρ = 2.7 g/cm³, rounded to 3 significant figures because the least precise input has 3.
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0/1500
Densities of common substances
Values at about 20 °C unless stated, from the CRC Handbook of Chemistry and Physics. A measured density within a few percent of one of these is good evidence of what your sample is.
| Substance | Density (g/cm³) |
|---|---|
| Air (20 °C, 1 atm) | 0.0012 |
| Ethanol | 0.789 |
| Ice | 0.917 |
| Water (4 °C) | 1.000 |
| Seawater | 1.025 |
| Aluminium | 2.70 |
| Iron | 7.87 |
| Copper | 8.96 |
| Silver | 10.49 |
| Lead | 11.34 |
| Mercury | 13.53 |
| Gold | 19.32 |
Worked example
A metal block has a mass of 54.0 g and displaces 20.0 mL of water. ρ = 54.0 ÷ 20.0 = 2.70 g/cm³, which matches aluminium.
Frequently asked questions
What is the density formula?
Density ρ = mass ÷ volume. In chemistry it is usually quoted in g/cm³ (same as g/mL); in physics in kg/m³. 1 g/cm³ = 1000 kg/m³.
How do I find the volume of an irregular object?
By water displacement: read a measuring cylinder, lower the object in, read again. The rise in level in mL equals the object’s volume in cm³.
Why does ice float?
Ice (0.917 g/cm³) is less dense than liquid water (1.000 g/cm³) because hydrogen bonds hold the molecules in an open hexagonal lattice. Anything less dense than a liquid floats in it.
Does density change with temperature?
Yes, slightly for liquids and solids and a lot for gases. Most substances expand when heated so their density falls. Water is unusual: it is densest at about 4 °C.