PSI to bar: tyre pressure
PSI to bar (atm) conversion table, a description of the units used to measure tyre pressure.
What units is tyre pressure measured in?
| PSI | Bar (atm) |
|---|---|
| 20 | 1.4 |
| 22 | 1.5 |
| 23 | 1.6 |
| 25 | 1.7 |
| 26 | 1.8 |
| 28 | 1.9 |
| 29 | 2.0 |
| 30 | 2.1 |
| 32 | 2.2 |
| 33 | 2.3 |
| PSI | Bar (atm) |
|---|---|
| 35 | 2.4 |
| 36 | 2.5 |
| 38 | 2.6 |
| 39 | 2.7 |
| 41 | 2.8 |
| 42 | 2.9 |
| 44 | 3.0 |
| 45 | 3.1 |
| 46 | 3.2 |
| 48 | 3.3 |
So, car makers usually give the recommended tyre pressure either on the inside of the fuel filler flap or on the door pillar in the driver’s door opening. The unit of measurement that makes the most sense to us is the bar (or technical atmosphere): that is exactly what tyre fitters’ pressure gauges use to measure tyre pressure. But this system of measuring tyre pressure is not used in every country, so there is another standard, measured in mysterious psi, which often leaves newly-minted car owners baffled when their recommended pressure is given precisely in those units.
Without going into detail, let’s just say that psi means pounds per square inch, and to get a pressure value in technical atmospheres you need to divide the psi figure by roughly 14.5 (nobody needs exact coefficients here, because the difference would not clear a pressure gauge’s margin of error). On the right is a table of the most common recommended pressure values, psi to bar.