Inches of Water to Millibars (inH₂O → mbar)
Formula
1 inH₂O = 2.49082 mbarConversion Table
| inH₂O | mbar |
|---|---|
| 0 | 0 |
| 1.0000 | 2.4908 |
| 2.0000 | 4.9816 |
| 3.0000 | 7.4725 |
| 4.0000 | 9.9633 |
| 5.0000 | 12.454 |
| 6.0000 | 14.945 |
| 7.0000 | 17.436 |
| 8.0000 | 19.927 |
| 9.0000 | 22.417 |
| 10.000 | 24.908 |
| 11.000 | 27.399 |
| 12.000 | 29.890 |
| 13.000 | 32.381 |
| 14.000 | 34.871 |
| 15.000 | 37.362 |
| 16.000 | 39.853 |
| 17.000 | 42.344 |
| 18.000 | 44.835 |
| 19.000 | 47.326 |
| inH₂O | mbar |
|---|---|
| 20.000 | 49.816 |
| 21.000 | 52.307 |
| 22.000 | 54.798 |
| 23.000 | 57.289 |
| 24.000 | 59.780 |
| 25.000 | 62.270 |
| 26.000 | 64.761 |
| 27.000 | 67.252 |
| 28.000 | 69.743 |
| 29.000 | 72.234 |
| 30.000 | 74.725 |
| 31.000 | 77.215 |
| 32.000 | 79.706 |
| 33.000 | 82.197 |
| 34.000 | 84.688 |
| 35.000 | 87.179 |
| 36.000 | 89.670 |
| 37.000 | 92.160 |
| 38.000 | 94.651 |
| 39.000 | 97.142 |
| inH₂O | mbar |
|---|---|
| 40.000 | 99.633 |
| 41.000 | 102.12 |
| 42.000 | 104.61 |
| 43.000 | 107.11 |
| 44.000 | 109.60 |
| 45.000 | 112.09 |
| 46.000 | 114.58 |
| 47.000 | 117.07 |
| 48.000 | 119.56 |
| 49.000 | 122.05 |
| 50.000 | 124.54 |
| 51.000 | 127.03 |
| 52.000 | 129.52 |
| 53.000 | 132.01 |
| 54.000 | 134.50 |
| 55.000 | 137.00 |
| 56.000 | 139.49 |
| 57.000 | 141.98 |
| 58.000 | 144.47 |
| 59.000 | 146.96 |
| inH₂O | mbar |
|---|---|
| 60.000 | 149.45 |
| 61.000 | 151.94 |
| 62.000 | 154.43 |
| 63.000 | 156.92 |
| 64.000 | 159.41 |
| 65.000 | 161.90 |
| 66.000 | 164.39 |
| 67.000 | 166.88 |
| 68.000 | 169.38 |
| 69.000 | 171.87 |
| 70.000 | 174.36 |
| 71.000 | 176.85 |
| 72.000 | 179.34 |
| 73.000 | 181.83 |
| 74.000 | 184.32 |
| 75.000 | 186.81 |
| 76.000 | 189.30 |
| 77.000 | 191.79 |
| 78.000 | 194.28 |
| 79.000 | 196.77 |
Inches of Water to Millibars Conversion
Converting Inches of Water (inH₂O) to Millibars (mbar) is a common pressure conversion. 1 inH₂O equals 2.49082 mbar. For example, 100 inH₂O is equal to 249.082 mbar.
Quick Reference Values
1 inH₂O = 2.49082 mbar. 5 inH₂O = 12.4541 mbar. 10 inH₂O = 24.9082 mbar. 25 inH₂O = 62.2705 mbar. 50 inH₂O = 124.541 mbar. 100 inH₂O = 249.082 mbar.
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].
What is Millibars?
Millibars (mbar) is a unit of pressure. The millibar is a unit of pressure equal to 100 pascals or 0.1 kilopascals. It is one-thousandth of a bar, which is defined as exactly 100,000 pascals in the International System of Units (SI). The millibar is commonly used in meteorology to measure atmospheric pressure and is recognized under ISO standards for pressure units [iso-80000]. The bar and its subunit, the millibar, were introduced by the German meteorologist Heinrich von Helmholtz in the early 20th century. The millibar was adopted as a practical unit for meteorological pressure measurements before SI units were formalized [nist-sp-811]. Millibars remain widely used in weather reports and aviation worldwide, especially in countries like the United States, United Kingdom, and Australia. Meteorological agencies, including NOAA and the UK Met Office, use millibars alongside pascals for atmospheric pressure [nist-sp-811].
Common Misspellings
People often search for this conversion using these alternate spellings: inch of water, inch-water, in h2o, inch h20, milibars, milibars, millibar, milibar. All of these refer to the Inches of Water to Millibars conversion.