The exact factor, and the shortcut
One bar is 14.5038 psi. The factor is fixed: a bar is exactly 100,000 pascals and a psi is 6,894.757 pascals. For a quick estimate, multiply bar by 14.5, or just add half again to the number and double it — 2 bar is roughly 29 psi.
Tire pressure, bar to psi
| Bar | PSI | kPa | Typical use |
|---|---|---|---|
| 1.8 | 26 | 180 | Underinflated |
| 2.0 | 29 | 200 | Small car, front |
| 2.2 | 32 | 220 | Passenger car |
| 2.4 | 35 | 240 | Passenger car, loaded |
| 2.7 | 39 | 270 | SUV / van |
| 3.0 | 44 | 300 | Overinflated for most cars |
Set pressure when tires are cold. The number on the tire sidewall is a maximum, not the recommended value.
Where you meet each unit
- Bar. The metric standard across Europe, used on tire placards, dive gear and industrial equipment. Roughly equal to sea-level air pressure (1 atm = 1.013 bar).
- PSI. Standard in the US, and common on air compressors, gauges and pneumatic tools everywhere. Workshop compressors run around 6 to 10 bar, or 90 to 145 psi.
- Scuba tanks. Filled to 200 to 300 bar, which is 2,900 to 4,400 psi — a reminder that the same factor spans a huge range.
Common questions
What is 1 bar in psi?
One bar is 14.5038 psi, usually rounded to 14.5. To go the other way, divide psi by 14.5038, so 30 psi is about 2.07 bar.
What tire pressure is 2.2 bar in psi?
2.2 bar is 32 psi, and 2.4 bar is 35 psi, the usual range for passenger cars. The exact figure for your car is on the sticker inside the driver door, not on the tire itself.
What is the difference between bar and barg?
Barg is gauge pressure, measured above the surrounding air. Bar or bara is absolute pressure, measured from a vacuum. Tire gauges read gauge pressure, so a "2.2 bar" tire is about 3.2 bar absolute once you add the atmosphere.
