Inches Of Mercury to Pascals (inHg to Pa)
1 inch of mercury equals 3,386.38864 pascals (rounded).
How to convert inches of mercury to pascals
To convert inches of mercury to pascals, multiply the number of inches of mercury by 3,386.38864. The factor is rounded to 10 significant digits. To go the other way, multiply pascals by 0.000295299833 (rounded).
pascals = inches of mercury × 3,386.38864
Example: 10 inches of mercury = 33,863.8864 pascals.
About these units
Inch Of Mercury (inHg)
About 3,386.39 pascals. US weather reports and aircraft altimeters quote barometric pressure in inches of mercury.
Barometers in the United States still speak in inches. The inch of mercury is the pressure exerted by a 1-inch (25.4 mm) column of mercury under standard gravity, which is a conventional value of about 3,386.389 pascals. Because mercury's density depends on temperature, older literature that used a 60 degrees Fahrenheit basis gives about 3,376.85 pascals instead.
Its modern home is weather and flying. US weather reports quote barometric pressure in inHg, and North America and Japan give altimeter settings in it. Aircraft at higher altitudes set their altimeters to a standard 29.92 inHg, which is where flight levels come from, and that number equals one standard atmosphere.
Mechanics know it from vacuum and boost gauges. Technicians describe refrigerant-system vacuum in inHg, automotive cooling system fill tools typically hold 22 to 27 inHg of vacuum, and railways once used it for vacuum brakes.
1 inch of mercury = 3,386.38864 pascals (approximately).
Sources: Wikipedia: Inch of mercury; Wikipedia: Standard atmosphere (unit); Wikipedia: Atmospheric pressure
Pascal (Pa)
The SI unit of pressure: one newton per square meter. A very small unit; atmospheric pressure is about 101,325 Pa.
Blaise Pascal never saw a pascal, because the name was adopted by the 14th CGPM in 1971 for the newton per square meter. He did, however, earn the honor. In 1647 he published experiments on the vacuum, and on 19 September 1648 his brother-in-law Florin Périer carried a mercury barometer up the Puy de Dôme near Clermont, where the column stood at about 23 inches against about 26 at the base. Pascal had reasoned that air pressure should fall with altitude, and the result confirmed it.
One pascal is a tiny pressure, so the unit is mostly met with prefixes. Standard atmospheric pressure is 101,325 Pa, a typical sea-level reading is about 1,013 hPa, and the threshold of hearing in air is taken as a reference pressure of 20 micropascals. Building airtightness tests, in contrast, are run at 50 Pa.
Pascal is also remembered for hydrostatics, where he showed that pressure depends on height difference rather than the weight of the fluid, and for the hydraulic press.
The pascal is the reference unit for pressure on this site.
Sources: Wikipedia: Pascal (unit); Wikipedia: Blaise Pascal
Related conversions
- Pascals to inches of mercury (reverse)
- Inches of mercury to kilopascals
- Inches of mercury to bars
- Inches of mercury to standard atmospheres
- Inches of mercury to PSI
- Inches of mercury to hectopascals
- Inches of mercury to megapascals
- Inches of mercury to millibars
- Inches of mercury to torr
- Inches of mercury to millimeters of mercury
- Kilopascals to pascals
- Bars to pascals
- Standard atmospheres to pascals
- PSI to pascals
- Hectopascals to pascals
- Megapascals to pascals
- Millibars to pascals
- Torr to pascals
- Millimeters of mercury to pascals
- Gigapascals to pascals
- Kilopounds per square inch to pascals
- Millimeters of water to pascals
See all pressure units.