›› Convert millimeter of water [4 C] to

millimeter of water
inch mercury

›› More information from the unit converter

How many millimeter of water in 1 inch mercury? The answer is 345.31557667501.
We assume you are converting between millimeter of water [4 C] and .
You can view more details on each measurement unit:
millimeter of water or inch mercury
The SI derived unit for pressure is the pascal.
1 pascal is equal to 0.10197162129779 millimeter of water, or 0.00029529980164712 inch mercury.
Note that rounding errors may occur, so always check the results.
Use this page to learn how to convert between millimeters of water and inches mercury.
Type in your own numbers in the form to convert the units!

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

1 millimeter of water to inch mercury = 0.0029 inch mercury

10 millimeter of water to inch mercury = 0.02896 inch mercury

50 millimeter of water to inch mercury = 0.1448 inch mercury

100 millimeter of water to inch mercury = 0.28959 inch mercury

200 millimeter of water to inch mercury = 0.57918 inch mercury

500 millimeter of water to inch mercury = 1.44795 inch mercury

1000 millimeter of water to inch mercury = 2.8959 inch mercury

›› Want other units?

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

Enter two units to convert


›› Common pressure conversions

millimeter of water to barad
millimeter of water to foot mercury
millimeter of water to megabar
millimeter of water to centimeter mercury
millimeter of water to inch of mercury
millimeter of water to newton/square millimeter
millimeter of water to centipascal
millimeter of water to pieze
millimeter of water to attobar
millimeter of water to inch of air

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widely used for barometric pressure in weather reports and aviation in the United States, but is considered somewhat outdated elsewhere.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

›› 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!