How to convert inches of mercury to hectopascals
Formula: hPa = inHg × 33.8639
Worked example: 29.92 inHg → 29.92 × 33.8639 = 1,013.21 hPa
Divide hectopascals by 33.8639 to get inches of mercury. Standard pressure, 1013.25 hPa, is 29.92 inHg; a deep low of 970 hPa reads 28.64 inHg on an American barometer.
Inches of mercury to hectopascals conversion chart
| Inches of mercury (inHg) | Hectopascals (hPa) |
|---|---|
| 28 inHg | 948.189 hPa |
| 28.5 inHg | 965.121 hPa |
| 29 inHg | 982.053 hPa |
| 29.5 inHg | 998.985 hPa |
| 29.92 inHg | 1,013.21 hPa |
| 30 inHg | 1,015.92 hPa |
| 30.5 inHg | 1,032.85 hPa |
| 31 inHg | 1,049.78 hPa |
What is an inch of mercury?
The inch of mercury, about 3,386.39 pascals, is how US weather reports and aircraft altimeters express barometric pressure. Standard pressure is 29.92 inHg; readings above 30.2 usually mean fair weather.
What is a hectopascal?
The hectopascal equals 100 pascals and is identical to the millibar. Weather maps and forecasts outside the US give air pressure in hectopascals; standard sea-level pressure is 1013.25 hPa, and a strong hurricane can drop below 950 hPa.