›› Convert to millimeter of water [4 °C]

inch mercury
millimeter of water

›› More information from the unit converter

How many inch mercury in 1 millimeter of water? The answer is 0.0028959017998228.
We assume you are converting between and millimeter of water [4 °C].
You can view more details on each measurement unit:
inch mercury or millimeter of water
The SI derived unit for pressure is the pascal.
1 pascal is equal to 0.00029529980164712 inch mercury, or 0.10197162129779 millimeter of water.
Note that rounding errors may occur, so always check the results.
Use this page to learn how to convert between inches mercury and millimeters of water.
Type in your own numbers in the form to convert the units!

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

1 inch mercury to millimeter of water = 345.31558 millimeter of water

2 inch mercury to millimeter of water = 690.63115 millimeter of water

3 inch mercury to millimeter of water = 1035.94673 millimeter of water

4 inch mercury to millimeter of water = 1381.26231 millimeter of water

5 inch mercury to millimeter of water = 1726.57788 millimeter of water

6 inch mercury to millimeter of water = 2071.89346 millimeter of water

7 inch mercury to millimeter of water = 2417.20904 millimeter of water

8 inch mercury to millimeter of water = 2762.52461 millimeter of water

9 inch mercury to millimeter of water = 3107.84019 millimeter of water

10 inch mercury to millimeter of water = 3453.15577 millimeter of water

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

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›› Common pressure conversions

inch mercury to ton/square inch
inch mercury to attopascal
inch mercury to zettapascal
inch mercury to millibar
inch mercury to decibar
inch mercury to kilogram-force/square meter
inch mercury to zeptobar
inch mercury to petabar
inch mercury to kilopascal
inch mercury to kip/square inch

›› Definition: Inch 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widely used for barometric pressure in weather reports and aviation in the United States, but is considered somewhat outdated elsewhere.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.

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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!