Hectopascals to Inches of Water (hPa → inH₂O)
Formula
1 hPa = 0.401474213311279 inH₂OConversion Table
| hPa | inH₂O |
|---|---|
| 0 | 0 |
| 1.0000 | 0.40147 |
| 2.0000 | 0.80295 |
| 3.0000 | 1.2044 |
| 4.0000 | 1.6059 |
| 5.0000 | 2.0074 |
| 6.0000 | 2.4088 |
| 7.0000 | 2.8103 |
| 8.0000 | 3.2118 |
| 9.0000 | 3.6133 |
| 10.000 | 4.0147 |
| 11.000 | 4.4162 |
| 12.000 | 4.8177 |
| 13.000 | 5.2192 |
| 14.000 | 5.6206 |
| 15.000 | 6.0221 |
| 16.000 | 6.4236 |
| 17.000 | 6.8251 |
| 18.000 | 7.2265 |
| 19.000 | 7.6280 |
| hPa | inH₂O |
|---|---|
| 20.000 | 8.0295 |
| 21.000 | 8.4310 |
| 22.000 | 8.8324 |
| 23.000 | 9.2339 |
| 24.000 | 9.6354 |
| 25.000 | 10.037 |
| 26.000 | 10.438 |
| 27.000 | 10.840 |
| 28.000 | 11.241 |
| 29.000 | 11.643 |
| 30.000 | 12.044 |
| 31.000 | 12.446 |
| 32.000 | 12.847 |
| 33.000 | 13.249 |
| 34.000 | 13.650 |
| 35.000 | 14.052 |
| 36.000 | 14.453 |
| 37.000 | 14.855 |
| 38.000 | 15.256 |
| 39.000 | 15.657 |
| hPa | inH₂O |
|---|---|
| 40.000 | 16.059 |
| 41.000 | 16.460 |
| 42.000 | 16.862 |
| 43.000 | 17.263 |
| 44.000 | 17.665 |
| 45.000 | 18.066 |
| 46.000 | 18.468 |
| 47.000 | 18.869 |
| 48.000 | 19.271 |
| 49.000 | 19.672 |
| 50.000 | 20.074 |
| 51.000 | 20.475 |
| 52.000 | 20.877 |
| 53.000 | 21.278 |
| 54.000 | 21.680 |
| 55.000 | 22.081 |
| 56.000 | 22.483 |
| 57.000 | 22.884 |
| 58.000 | 23.286 |
| 59.000 | 23.687 |
| hPa | inH₂O |
|---|---|
| 60.000 | 24.088 |
| 61.000 | 24.490 |
| 62.000 | 24.891 |
| 63.000 | 25.293 |
| 64.000 | 25.694 |
| 65.000 | 26.096 |
| 66.000 | 26.497 |
| 67.000 | 26.899 |
| 68.000 | 27.300 |
| 69.000 | 27.702 |
| 70.000 | 28.103 |
| 71.000 | 28.505 |
| 72.000 | 28.906 |
| 73.000 | 29.308 |
| 74.000 | 29.709 |
| 75.000 | 30.111 |
| 76.000 | 30.512 |
| 77.000 | 30.914 |
| 78.000 | 31.315 |
| 79.000 | 31.716 |
Hectopascals to Inches of Water Conversion
Converting Hectopascals (hPa) to Inches of Water (inH₂O) is a common pressure conversion. 1 hPa equals 0.401474 inH₂O. For example, 100 hPa is equal to 40.147421 inH₂O.
Quick Mental Math: Hectopascals to Inches of Water
Pressure units (atm, bar, psi, pascal) are diverse; use atmospheres as a reference tier.
Why is converting Hectopascals to Inches of Water tricky?
Magnitude or direction confusion between hectopascals and inches-of-water is the primary error source.
Quick Reference Values
1 hPa = 0.401474 inH₂O. 5 hPa = 2.007371 inH₂O. 10 hPa = 4.014742 inH₂O. 25 hPa = 10.036855 inH₂O. 50 hPa = 20.073711 inH₂O. 100 hPa = 40.147421 inH₂O.
What is Hectopascals?
Hectopascals (hPa) is a unit of pressure. The hectopascal is a unit of pressure equal to 100 pascals. It is defined as exactly 100 newtons per square meter (100 N/m²), where the pascal (Pa) is the SI derived unit of pressure. The hectopascal is widely used in meteorology for atmospheric pressure measurements and aligns with the SI system as per international standards [bipm-si-brochure]. The pascal unit was named after Blaise Pascal and officially adopted by the General Conference on Weights and Measures (CGPM) in 1971. The hectopascal emerged as a convenient multiple used in meteorology to represent atmospheric pressure values in the 20th century [cgpm-resolutions]. Hectopascals are standard in weather reports worldwide, especially in Europe, Asia, and Australia. The US National Weather Service uses millibars, numerically equivalent to hectopascals, for atmospheric pressure. It is recognized by ISO 80000 as a unit of pressure [iso-80000].
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: hecto pascals, hecto-pascals, hecto pascal, hec topascal, inch of water, inch-water, in h2o, inch h20. All of these refer to the Hectopascals to Inches of Water conversion.