Pressure Converter: Convert hPa, inHg, mb, kPa, atm and psi
Convert the reading, then check the trend: Convert atmospheric pressure between hectopascals (hPa/mb), inches of mercury, mmHg, kPa, atm and psi, with charts and weather reference points.
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Interpret the pressure and its direction
Near standard sea-level pressure
A steady reading near 1013 hPa is a neutral baseline. The local trend is often more useful than the number alone.
Compare sea-level-adjusted pressure with sea-level-adjusted pressure. A raw station reading falls naturally with elevation.
What a pressure number can and cannot tell you
US weather reports use inches of mercury, the rest of the world uses hectopascals (identical to millibars), and aviation altimeters mix both. Enter a pressure in any unit to see all the others.
For the evidence, limits and practical use behind this result, read Barometric Pressure. The weather tools guide explains when each calculator is the right one.
1 inHg = 33.864 hPa1 atm = 1013.25 hPa1 hPa = 1 mb
How meteorologists read pressure
- Memorize one number: 1013.25 hPa = 29.92 inHg. Everything else is relative to it.
- The trend beats the value: a steady 1005 hPa is calmer weather than 1015 hPa falling fast.
- hPa and mb are identical - no conversion needed, only the name changed.
Pressure reference points
| Reading | hPa | inHg | Meaning |
|---|---|---|---|
| Strongest recorded high | 1,084 | 32.01 | Agata, Siberia (1968) |
| Strong high pressure | 1,040 | 30.71 | Settled, clear weather |
| Standard sea level | 1,013.25 | 29.92 | Baseline for altimeters |
| Deep low / storm | 980 | 28.94 | Wind and precipitation likely |
| Major hurricane core | 920 | 27.17 | Category 5 territory |
| Lowest ever recorded | 870 | 25.69 | Typhoon Tip (1979) |
Pressure conversion chart
| hPa | inHg | mmHg | kPa | atm | psi |
|---|---|---|---|---|---|
| 950 | 28.05 | 712.56 | 95 | 0.94 | 13.78 |
| 980 | 28.94 | 735.06 | 98 | 0.97 | 14.21 |
| 1,000 | 29.53 | 750.06 | 100 | 0.99 | 14.5 |
| 1,013 | 29.92 | 760 | 101.33 | 1 | 14.7 |
| 1,020 | 30.12 | 765.07 | 102 | 1.01 | 14.79 |
| 1,040 | 30.71 | 780.07 | 104 | 1.03 | 15.08 |
| 1,050 | 31.01 | 787.57 | 105 | 1.04 | 15.23 |
Pressure, altimeter and weather questions
Are hectopascals and millibars the same?
Yes - 1 hPa equals exactly 1 mb. Meteorology renamed millibars to hectopascals when adopting SI units; the numbers never changed.
What is normal barometric pressure in inHg?
29.92 inHg (1013.25 hPa) at sea level. Everyday weather typically swings between about 28.9 and 30.7 inHg.
Why do altimeters need a pressure setting?
Aircraft altimeters infer altitude from pressure, so pilots dial in the local sea-level pressure (QNH) to read true altitude as weather systems move through.