Pressure unit converter
Type a pressure in any box and the other three update. Works for hPa, inHg, mmHg and kPa.
BaroLog, the barometer app these tools come from, shows pressure in the same four units and uses the same factors. Get it on Google Play.
How the conversion works
Each unit is a fixed multiple of the others, so converting is one multiplication. The tool converts through hPa:
| To get | From hPa |
|---|---|
| inHg | hPa × 0.02953 |
| mmHg | hPa × 0.75006 |
| kPa | hPa ÷ 10 |
Going the other way, 1 inHg is 33.864 hPa, 1 mmHg is 1.3332 hPa and 1 kPa is 10 hPa. The tool keeps more digits than shown here.
Worked example
A weather report gives 30.13 inHg and you want hPa. Divide by 0.02953: about 1020.32 hPa. From there, 1020.32 hPa × 0.75006 is 765.30 mmHg, and 1020.32 hPa ÷ 10 is 102.032 kPa.
Common values
| hPa | inHg | mmHg | kPa |
|---|---|---|---|
| 960 | 28.35 | 720.1 | 96.00 |
| 980 | 28.94 | 735.1 | 98.00 |
| 990 | 29.23 | 742.6 | 99.00 |
| 1000 | 29.53 | 750.1 | 100.00 |
| 1010 | 29.83 | 757.6 | 101.00 |
| 1013.25 | 29.92 | 760.0 | 101.33 |
| 1020 | 30.12 | 765.1 | 102.00 |
| 1030 | 30.42 | 772.6 | 103.00 |
| 1040 | 30.71 | 780.1 | 104.00 |
1013.25 hPa is the standard atmosphere at sea level, a reference value. The air around you is rarely exactly that.
Limits
- Results are rounded to 2 or 3 decimals. Your barometer is unlikely to be more exact than that.
- inHg and mmHg are defined for a column of mercury under standard conditions. These factors are the standard ones, and they do not correct for the temperature of a real mercury barometer.
- This page changes units only. It doesn't tell you what the weather will do. For that, see how to read a barometer.
Frequently asked
Is a millibar the same as a hectopascal? Yes. 1 mbar is exactly 1 hPa, so use the hPa box for a reading in millibars.
Is mmHg the same as torr? Almost. The two differ by less than one part in a million, far less than any barometer can show.
Can I convert a change in pressure as well as a reading? Yes. The factors are the same. A fall of 5 hPa is a fall of 0.15 inHg or 3.8 mmHg.
Does this convert station pressure to sea-level pressure? No. A converter changes the unit, not the place the pressure refers to. Use the sea-level pressure calculator for that.