Millimeters of water conversion

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Millimeters of water


  • mm H2O
  • mm WC

Unit of:

  • Pressure

Worldwide use:

  • mm of water is most commonly used to describe how much water clothes and tents can withstand without leaking
  • mm of mercury is commonly used worldwide, particularly in medicine (to measure bloody pressure, etc.) and meteorology


1 mm of water is the pressure exerted by a 1 mm high column of water

Usage context:

Mostly used for describing water resistance of clothes and tents.