What Is the Density of Water?

Close up of water against a blue background.

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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, there are more precise values for you to use.

The density of pure water actually is somewhat ​less than 1 g/cm3. 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