Humidity converter
Convert relative humidity into the actual water in the air. Pick the temperature first: warm air holds far more water than cold.
That's 1.21× as humid as desert air, while cold winter air is 1.65× wetter. A 50 m³ room at that level holds about 121.2 mL of water.
What it means
How much water is in the air?
Saturation values come from the Magnus formula, accurate to about 0.1% between −40 and 50 °C.
Every unit
Your humidity in every unit
Learn
Three things worth knowing
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Warm air holds much more water
Saturation roughly doubles every 10 °C: 4.8 g/m³ at 0 °C, 9.4 at 10, 17.3 at 20 and 30.4 at 30.
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Why windows run with water
Air at 20 °C and 50% holds 8.7 g/m³. Cool it against a cold pane to 8 °C and that is already saturation, so the surplus condenses.
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Relative humidity alone means little
80% in a Scottish winter is drier air than 40% in a Cairo summer. Without a temperature, a relative humidity does not say how much water there is.
Shortcuts
Popular humidity conversions
Background
About humidity
Relative humidity is a percentage of what the air could hold at its current temperature — so the same 50% means 4.8 g/m³ at 10 °C and 15.2 g/m³ at 30 °C, three times as much water.
Absolute humidity in g/m³ is the real amount, and it does not change when you heat the air. That is why heating a room drops the relative humidity without removing a drop of water.