Inches of mercury, (inHg and "Hg) is a unit of measurement for pressure. It is still used for barometric pressure in weather reports, refrigeration and Aviation in the United States.

It is the pressure exerted by a column of mercury of 1 inch (2.54 cm) in height at the standard acceleration of gravity. Conversion to metric units depends on the temperature of mercury, and hence its density; typical conversion factors are:

Conditions Pressure
conventional 3386.389 Pascals
32°F 3386.38 Pascals
60°F 3376.85 Pascals

See also