Density of Water

As with anything, the density of water is dependent upon temperature.  The odd thing about liquid water is that when its temperature is lowered to the point of becoming a solid it actually becomes less dense.  You may have heard of this solid substance – it’s called ice.  You may have also noticed that ice floats, and this is a result of this interesting water density phenomenon.

What Is The Density of Water?

The density of water at room temperature is 1,000 kg/m³.  This means at room temperature 1,000 kg of water will take up approximately 1 cubic meter.  It is actually not precisely 1, but rather very close.  It does indeed become more dense – approaching closer to 1,000 kg/m³.  Water is actually most dense at 4°C, and then the density decreases minimally until it reaches freezing temperature (0°C or 32°F) at which point the density of ice becomes almost 10% less dense than liquid water.  This is a result of the molecular structure of ice.  Fewer H20 molecules can fit into the same space due to the rigid structure caused by the hydrogen bonds in water, which decreases the density.  This relationship between the density of water and ice is a rare one, and few other substances share this property.

A Table of The Density of Water At Different Temperatures

Temp (°C) Density (kg/m3)
100 958.4
80 971.8
60 983.2
40 992.2
30 995.65
25 997.05
22 997.77
20 998.21
15 999.1
10 999.7
4 999.97
0 999.84
−10 998.12
−20 993.55
−30 983.85

The information for this water density table is from

Amongst the density of water at various temperatures, you can see that freezing temperature is highlighted there.  Notice how the density increases up until 4°C, hits freezing, and then rapidly decreases.

The density of salt water is dependent upon the concentration of salt disolved in the water.  Sea water with the lowest concentrations of salt are located around the Equator, while those with the highest concentrations are located at the poles.

You should now have a better understanding about how the density of water works.

1 Comment

  1. The Density of water in the description has been shown 1 kg/m^3 while in the table of density at different temperatures it is wrongly shown as more that 900 kg/m^3 while the figure should be 0.999 or so kg/m^3. or it should be 1000 kg/m^3. It may be corrected please.

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