Atmospheres to Inches of Water (atm → inH₂O)
Formula
1 atm = 406.7937466376535 inH₂OConversion Table
| atm | inH₂O |
|---|---|
| 0 | 0 |
| 1.0000 | 406.79 |
| 2.0000 | 813.59 |
| 3.0000 | 1,220.4 |
| 4.0000 | 1,627.2 |
| 5.0000 | 2,034.0 |
| 6.0000 | 2,440.8 |
| 7.0000 | 2,847.6 |
| 8.0000 | 3,254.3 |
| 9.0000 | 3,661.1 |
| 10.000 | 4,067.9 |
| 11.000 | 4,474.7 |
| 12.000 | 4,881.5 |
| 13.000 | 5,288.3 |
| 14.000 | 5,695.1 |
| 15.000 | 6,101.9 |
| 16.000 | 6,508.7 |
| 17.000 | 6,915.5 |
| 18.000 | 7,322.3 |
| 19.000 | 7,729.1 |
| atm | inH₂O |
|---|---|
| 20.000 | 8,135.9 |
| 21.000 | 8,542.7 |
| 22.000 | 8,949.5 |
| 23.000 | 9,356.3 |
| 24.000 | 9,763.0 |
| 25.000 | 10,170 |
| 26.000 | 10,577 |
| 27.000 | 10,983 |
| 28.000 | 11,390 |
| 29.000 | 11,797 |
| 30.000 | 12,204 |
| 31.000 | 12,611 |
| 32.000 | 13,017 |
| 33.000 | 13,424 |
| 34.000 | 13,831 |
| 35.000 | 14,238 |
| 36.000 | 14,645 |
| 37.000 | 15,051 |
| 38.000 | 15,458 |
| 39.000 | 15,865 |
| atm | inH₂O |
|---|---|
| 40.000 | 16,272 |
| 41.000 | 16,679 |
| 42.000 | 17,085 |
| 43.000 | 17,492 |
| 44.000 | 17,899 |
| 45.000 | 18,306 |
| 46.000 | 18,713 |
| 47.000 | 19,119 |
| 48.000 | 19,526 |
| 49.000 | 19,933 |
| 50.000 | 20,340 |
| 51.000 | 20,746 |
| 52.000 | 21,153 |
| 53.000 | 21,560 |
| 54.000 | 21,967 |
| 55.000 | 22,374 |
| 56.000 | 22,780 |
| 57.000 | 23,187 |
| 58.000 | 23,594 |
| 59.000 | 24,001 |
| atm | inH₂O |
|---|---|
| 60.000 | 24,408 |
| 61.000 | 24,814 |
| 62.000 | 25,221 |
| 63.000 | 25,628 |
| 64.000 | 26,035 |
| 65.000 | 26,442 |
| 66.000 | 26,848 |
| 67.000 | 27,255 |
| 68.000 | 27,662 |
| 69.000 | 28,069 |
| 70.000 | 28,476 |
| 71.000 | 28,882 |
| 72.000 | 29,289 |
| 73.000 | 29,696 |
| 74.000 | 30,103 |
| 75.000 | 30,510 |
| 76.000 | 30,916 |
| 77.000 | 31,323 |
| 78.000 | 31,730 |
| 79.000 | 32,137 |
Atmospheres to Inches of Water Conversion
Converting Atmospheres (atm) to Inches of Water (inH₂O) is a common pressure conversion. 1 atm equals 406.793747 inH₂O. For example, 100 atm is equal to 40,679.374664 inH₂O.
Quick Mental Math: Atmospheres to Inches of Water
Multiply atmospheres by approximately 406.78 to convert to inches-of-water.
Why is converting Atmospheres to Inches of Water tricky?
The non-integer multiplier 406.78 is imprecise for mental estimation.
Quick Reference Values
1 atm = 406.793747 inH₂O. 5 atm = 2,033.968733 inH₂O. 10 atm = 4,067.937466 inH₂O. 25 atm = 10,169.843666 inH₂O. 50 atm = 20,339.687332 inH₂O. 100 atm = 40,679.374664 inH₂O.
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].
What is Inches of Water?
Inches of Water (inH₂O) is a unit of pressure. Inches of water measure pressure as the height in inches of a water column. One inch of water equals 249.0889 pascals (Pa) at 4 °C. This unit is widely used to measure low-pressure differentials in HVAC and fluid systems [nist-si-guide]. The use of water columns for pressure measurement dates to early fluid mechanics studies. The inch unit was adopted in English-speaking countries for practical low-pressure measurement. It remains standardized for building and industrial applications [nist-si-guide]. Inches of water are used primarily in the United States for HVAC duct pressures, gas pressure measurements, and cleanroom environments. Other countries often use pascals or millimeters of water but recognize inH2O in specific sectors [nist-si-guide].
Common Misspellings
People often search for this conversion using these alternate spellings: atmosphers, atmosfere, atmospere, atmospherics, inch of water, inch-water, in h2o, inch h20. All of these refer to the Atmospheres to Inches of Water conversion.