How to use
- Type a pressure in Value, such as a tyre pressure of 32.
- Pick the From and To units, or tap a popular conversion.
- Read the answer. Exact factors show “=”; mercury units show “≈”.
How the conversion works
Every unit has a size in pascals (Pa). The converter turns your value into pascals, then into the unit you want:
| Unit | Size |
|---|---|
| 1 bar | 100,000 Pa = 100 kPa ≈ 14.504 psi |
| 1 psi | ≈ 6,894.76 Pa ≈ 6.895 kPa |
| 1 standard atmosphere | 101,325 Pa ≈ 14.696 psi |
| 1 hPa | 1 mbar = 100 Pa |
| 1 mmHg | ≈ 133.322 Pa |
The psi is exact: it comes from the defined pound, the standard pull of gravity and the inch.
Examples
- 32 psi to bar: 32 × 6,894.757 ÷ 100,000 = 2.21 bar (220.6 kPa)
- 2.5 bar to psi: 36.26 psi
- 120 mmHg to kPa: 16 kPa
Conversion charts
Tyre pressures
| psi | bar | kPa |
|---|---|---|
| 26 psi | 1.79 | 179 |
| 28 psi | 1.93 | 193 |
| 30 psi | 2.07 | 207 |
| 32 psi | 2.21 | 221 |
| 35 psi | 2.41 | 241 |
| 36 psi | 2.48 | 248 |
| 40 psi | 2.76 | 276 |
| 44 psi | 3.03 | 303 |
Use the cold pressure on your vehicle’s door-jamb placard or in the owner’s manual, not the maximum printed on the tyre.
| bar | psi |
|---|---|
| 1.8 bar | 26.1 psi |
| 2 bar | 29 psi |
| 2.2 bar | 31.9 psi |
| 2.4 bar | 34.8 psi |
| 2.5 bar | 36.3 psi |
| 3 bar | 43.5 psi |
Weather pressures
| hPa (mbar) | inHg | mmHg |
|---|---|---|
| 980 | 28.94 | 735.1 |
| 1,000 | 29.53 | 750.1 |
| 1,013.25 | 29.92 | 760 |
| 1,020 | 30.12 | 765.1 |
| 1,040 | 30.71 | 780.1 |
More detail: gauge pressure and mercury units
- Gauge vs absolute: tyre gauges read pressure above the surrounding air. Absolute pressure adds the air pressure itself, about 1 atmosphere at sea level. The units are the same; only the zero point differs.
- mbar and hPa are the same size, so weather maps can use either.
- mmHg and torr differ by less than 1 part in 7 million.
- Mercury units use conventional values, so their factors are shown with “≈”.
Weather forecast in °F? Use the temperature converter.