How to use this calculator
- Choose what to solve for.
- Enter the known values and choose their units.
- Density is shown in several units, along with specific gravity relative to water.
Formula
Density is mass per unit volume. Specific gravity compares a substance's density with that of water (about 1,000 kg/m³ at 4 °C).
ρ = m / V
m = ρ × V
V = m / ρ
1 g/cm³ = 1,000 kg/m³ = 62.428 lb/ft³
Example
- 500 g in 200 cm³: ρ = 500 / 200 = 2.5 g/cm³ = 2,500 kg/m³.
- Specific gravity ≈ 2.5, so it sinks in water. That's similar to glass or aluminum (2.7 g/cm³).
Frequently asked questions
What are some common densities?
Water 1.00 g/cm³, ice 0.92, aluminum 2.70, steel about 7.85, copper 8.96, gold 19.3, air about 0.0012 g/cm³ at sea level.
Does density change with temperature?
Yes, most materials expand when heated, so their density decreases. Gases are much more sensitive than solids or liquids.
What's the difference between density and specific gravity?
Density has units (such as kg/m³); specific gravity is the unitless ratio to water's density.