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/cm^{3}). While you can round the density to 1 gram per milliliter, there are more precise values for you to use.

The density of pure water actually is somewhat *less* than 1 g/cm^{3}. A standard table lists the values for the density of liquid water. Note that water can be supercooled and remain a 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