The density of pure water is approximately 1 gram per cubic centimeter (g/cm³) or 1000 kilograms per cubic meter (kg/m³) at around 4°C, where it reaches its maximum density
. This value can slightly vary with temperature: water is densest at about 4°C and becomes less dense both above and below this temperature due to thermal expansion and molecular structure changes
. For example, at 0°C, the density is slightly less than 1 g/cm³, and at 100°C, it decreases further to about 0.958 g/cm³
. Additionally, dissolved substances like salts increase water's density beyond that of pure water
. In summary:
- Density of pure water ≈ 1 g/cm³ (1000 kg/m³) at 4°C
- Density decreases at temperatures above or below 4°C
- Ice is less dense than liquid water, which is why it floats
- Dissolved substances increase water density
