What Is the Density of Water?

Temperature Affects Water Density

The maximum density of water is around 4 degrees Celsius, but it can be supercooled below its freezing point. If you disturb supercooled water, it will suddenly crystallize into ice.
The maximum density of water is around 4 degrees Celsius, but it can be supercooled below its freezing point. If you disturb supercooled water, it will suddenly crystallize into ice. Frank Cezus, Getty Images
by Anne Marie Helmenstine, Ph.D.
Updated April 12, 2018

The density of water is the weight of the water per its unit volume, which depends on the temperature of the water. The usual value used in calculations is 1 gram per milliliter (1 g/ml) or 1 gram per cubic centimeter (1 g/cm3). While you can round the density to 1 gram per milliliter, here are more precise values for you.

The density of pure water actually is somewhat ​less than 1 g/cm3. Here's a table listing the values for the density of liquid water. Note that water can be supercooled where it remains liquid well below its normal freezing point. The maximum density of water occurs around 4 degrees Celsius. Ice is less dense than liquid water, so it floats.

Temp (°C)    Density (kg/m3)

+100    958.4

+80     971.8

+60     983.2

+40     992.2

+30     995.6502

+25     997.0479

+22     997.7735

+20     998.2071

+15     999.1026

+10     999.7026

+4     999.9720

0       999.8395

−10     998.117

−20    993.547

−30     983.854