How to convert hectopascals to inches of mercury
Formula: inHg = hPa × 0.02953
Worked example: 1,013.25 hPa → 1,013.25 × 0.02953 = 29.9213 inHg
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.
Hectopascals to inches of mercury conversion chart
| Hectopascals (hPa) | Inches of mercury (inHg) |
|---|---|
| 950 hPa | 28.0535 inHg |
| 960 hPa | 28.3488 inHg |
| 970 hPa | 28.6441 inHg |
| 980 hPa | 28.9394 inHg |
| 990 hPa | 29.2347 inHg |
| 1,000 hPa | 29.53 inHg |
| 1,010 hPa | 29.8253 inHg |
| 1,013.25 hPa | 29.9213 inHg |
| 1,020 hPa | 30.1206 inHg |
| 1,030 hPa | 30.4159 inHg |
| 1,040 hPa | 30.7112 inHg |
| 1,050 hPa | 31.0065 inHg |
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.
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.