Inches of Mercury to Atmospheres (inHg → atm)
Formula
1 inHg = 0.033421060942511724 atmConversion Table
| inHg | atm |
|---|---|
| 0 | 0 |
| 1.0000 | 0.033421 |
| 2.0000 | 0.066842 |
| 3.0000 | 0.10026 |
| 4.0000 | 0.13368 |
| 5.0000 | 0.16711 |
| 6.0000 | 0.20053 |
| 7.0000 | 0.23395 |
| 8.0000 | 0.26737 |
| 9.0000 | 0.30079 |
| 10.000 | 0.33421 |
| 11.000 | 0.36763 |
| 12.000 | 0.40105 |
| 13.000 | 0.43447 |
| 14.000 | 0.46789 |
| 15.000 | 0.50132 |
| 16.000 | 0.53474 |
| 17.000 | 0.56816 |
| 18.000 | 0.60158 |
| 19.000 | 0.63500 |
| inHg | atm |
|---|---|
| 20.000 | 0.66842 |
| 21.000 | 0.70184 |
| 22.000 | 0.73526 |
| 23.000 | 0.76868 |
| 24.000 | 0.80211 |
| 25.000 | 0.83553 |
| 26.000 | 0.86895 |
| 27.000 | 0.90237 |
| 28.000 | 0.93579 |
| 29.000 | 0.96921 |
| 30.000 | 1.0026 |
| 31.000 | 1.0361 |
| 32.000 | 1.0695 |
| 33.000 | 1.1029 |
| 34.000 | 1.1363 |
| 35.000 | 1.1697 |
| 36.000 | 1.2032 |
| 37.000 | 1.2366 |
| 38.000 | 1.2700 |
| 39.000 | 1.3034 |
| inHg | atm |
|---|---|
| 40.000 | 1.3368 |
| 41.000 | 1.3703 |
| 42.000 | 1.4037 |
| 43.000 | 1.4371 |
| 44.000 | 1.4705 |
| 45.000 | 1.5039 |
| 46.000 | 1.5374 |
| 47.000 | 1.5708 |
| 48.000 | 1.6042 |
| 49.000 | 1.6376 |
| 50.000 | 1.6711 |
| 51.000 | 1.7045 |
| 52.000 | 1.7379 |
| 53.000 | 1.7713 |
| 54.000 | 1.8047 |
| 55.000 | 1.8382 |
| 56.000 | 1.8716 |
| 57.000 | 1.9050 |
| 58.000 | 1.9384 |
| 59.000 | 1.9718 |
| inHg | atm |
|---|---|
| 60.000 | 2.0053 |
| 61.000 | 2.0387 |
| 62.000 | 2.0721 |
| 63.000 | 2.1055 |
| 64.000 | 2.1389 |
| 65.000 | 2.1724 |
| 66.000 | 2.2058 |
| 67.000 | 2.2392 |
| 68.000 | 2.2726 |
| 69.000 | 2.3061 |
| 70.000 | 2.3395 |
| 71.000 | 2.3729 |
| 72.000 | 2.4063 |
| 73.000 | 2.4397 |
| 74.000 | 2.4732 |
| 75.000 | 2.5066 |
| 76.000 | 2.5400 |
| 77.000 | 2.5734 |
| 78.000 | 2.6068 |
| 79.000 | 2.6403 |
Inches of Mercury to Atmospheres Conversion
Converting Inches of Mercury (inHg) to Atmospheres (atm) is a common pressure conversion. 1 inHg equals 0.033421 atm. For example, 100 inHg is equal to 3.342106 atm.
Quick Mental Math: Inches of Mercury to Atmospheres
Divide inches-of-mercury by approximately 29.92 to convert to atmospheres.
Why is converting Inches of Mercury to Atmospheres tricky?
The non-integer divisor 29.92 requires careful mental arithmetic.
Quick Reference Values
1 inHg = 0.033421 atm. 5 inHg = 0.167105 atm. 10 inHg = 0.334211 atm. 25 inHg = 0.835527 atm. 50 inHg = 1.671053 atm. 100 inHg = 3.342106 atm.
What is Inches of Mercury?
Inches of Mercury (inHg) is a unit of pressure. Inches of mercury measure pressure as the height of a mercury column in inches exerted by atmospheric or other pressures. One inch of mercury equals exactly 3,386.389 pascals (Pa). This unit is commonly used in barometry and aviation altimetry [nist-si-guide]. The unit originates from mercury barometers developed by Evangelista Torricelli in 1643. Measuring pressure via mercury column height became standard in meteorology and aviation. The inch unit was adapted for use in English-speaking countries [nist-si-guide]. Inches of mercury are used mainly in the United States and Canada for weather reports and aircraft altimeters. Internationally, the pascal is preferred, but inHg remains common in aviation and HVAC industries [nist-si-guide].
What is Atmospheres?
Atmospheres (atm) is a unit of pressure. One atmosphere (atm) is a unit of pressure defined as exactly 101,325 pascals (Pa). It approximates the average air pressure at sea level on Earth. The atmosphere unit is used for expressing pressures in meteorology and engineering [iso-80000]. The atmosphere was originally defined in the 19th century based on average sea-level air pressure. It was standardized by the International Union of Pure and Applied Chemistry (IUPAC) and other bodies to equal 101,325 Pa in the mid-20th century [nist-sp-811]. Atmospheres are used worldwide in scientific fields, including chemistry and physics, and in engineering applications like pressure vessel design. It is less common in everyday use outside these fields [nist-sp-811].
Common Misspellings
People often search for this conversion using these alternate spellings: inch of mercury, inch-mercury, in hg, inches mercury, atmosphers, atmosfere, atmospere, atmospherics. All of these refer to the Inches of Mercury to Atmospheres conversion.