›› Convert millimeter water [4 °C] to inch of mercury [0 °C]

millimeter water
inch of mercury

›› More information from the unit converter

How many millimeter water in 1 inch of mercury? The answer is 345.31554268447.
We assume you are converting between millimeter water [4 °C] and inch of mercury [0 °C].
You can view more details on each measurement unit:
millimeter water or inch of mercury
The SI derived unit for pressure is the pascal.
1 pascal is equal to 0.10197162129779 millimeter water, or 0.00029529983071445 inch of mercury.
Note that rounding errors may occur, so always check the results.
Use this page to learn how to convert between millimeters water and inches of mercury.
Type in your own numbers in the form to convert the units!

›› Quick conversion chart of millimeter water to inch of mercury

1 millimeter water to inch of mercury = 0.0029 inch of mercury

10 millimeter water to inch of mercury = 0.02896 inch of mercury

50 millimeter water to inch of mercury = 0.1448 inch of mercury

100 millimeter water to inch of mercury = 0.28959 inch of mercury

200 millimeter water to inch of mercury = 0.57918 inch of mercury

500 millimeter water to inch of mercury = 1.44795 inch of mercury

1000 millimeter water to inch of mercury = 2.8959 inch of mercury

›› Want other units?

You can do the reverse unit conversion from inch of mercury to millimeter water, or enter any two units below:

Enter two units to convert


›› Common pressure conversions

millimeter water to pound/square foot
millimeter water to centimeter mercury
millimeter water to kilogram-force/square meter
millimeter water to meter of head
millimeter water to ton/square meter
millimeter water to zeptopascal
millimeter water to femtopascal
millimeter water to barad
millimeter water to pieze
millimeter water to gigabar

›› Definition: Inch of mercury

Inches of mercury or inHg is a non-SI unit for pressure. It is still widely used for barometric pressure in weather reports and aviation in the United States, but is considered somewhat outdated elsewhere.

It is defined as the pressure exerted by a column of mercury of 1 inch in height at 32 °F (0 °C) at the standard acceleration of gravity.

1 inHg = 3,386.389 pascals at 0 °C.

Aircraft operating at higher altitudes (above 18,000 feet) set their barometric altimeters to a standard pressure of 29.92 inHg or 1,013.2 hPa (1 hPa = 1 mbar) regardless of the actual sea level pressure, with inches of mercury used in the U.S. and Canada. The resulting altimeter readings are known as flight levels.

Piston engine aircraft with constant-speed propellers also use inHg to measure manifold pressure, which is indicative of engine power produced.

›› Metric conversions and more

ConvertUnits.com provides an online conversion calculator for all types of measurement units. You can find metric conversion tables for SI units, as well as English units, currency, and other data. Type in unit symbols, abbreviations, or full names for units of length, area, mass, pressure, and other types. Examples include mm, inch, 100 kg, US fluid ounce, 6'3", 10 stone 4, cubic cm, metres squared, grams, moles, feet per second, and many more!