Guide · Published October 28, 2026 · By the site maintainer
PSI to bar and kPa: tire and gauge pressure converted
Multiply psi by 0.06895 to get bar, or by 6.895 to get kilopascals. To go back, multiply bar by 14.504 to get psi. Almost every pressure conversion a driver or cyclist ever needs is one of those three, because the United States labels pressure in psi, Europe labels it in bar, and engineering specifications use kilopascals.
The psi (pounds per square inch) is a US customary and Imperial unit. The bar is not formally part of the SI system, but it is the working pressure unit across Europe and is defined as exactly 100,000 pascals, which makes the kilopascal a simple decimal shift away: 1 bar is exactly 100 kPa. That clean relationship is why the three units coexist so comfortably on the same pump gauge.
The formulas
- psi → bar: bar = psi × 0.0689476
- psi → kPa: kPa = psi × 6.89476
- bar → psi: psi = bar × 14.5038
- kPa → psi: psi = kPa × 0.145038
- bar → kPa: kPa = bar × 100 (exact)
For mental arithmetic, one anchor does most of the work: 30 psi is almost exactly 2 bar. Every additional 15 psi adds roughly one more bar, so 45 psi is about 3.1 bar and 60 psi is about 4.1 bar. It is not exact, but it is close enough to tell whether a gauge reading is in the right neighborhood before you reach for the precise figure.
Conversion table
| psi | bar | kPa |
|---|---|---|
| 26 psi | 1.79 bar | 179 kPa |
| 28 psi | 1.93 bar | 193 kPa |
| 30 psi | 2.07 bar | 207 kPa |
| 32 psi | 2.21 bar | 221 kPa |
| 33 psi | 2.28 bar | 228 kPa |
| 35 psi | 2.41 bar | 241 kPa |
| 36 psi | 2.48 bar | 248 kPa |
| 38 psi | 2.62 bar | 262 kPa |
| 40 psi | 2.76 bar | 276 kPa |
| 44 psi | 3.03 bar | 303 kPa |
| 50 psi | 3.45 bar | 345 kPa |
| 60 psi | 4.14 bar | 414 kPa |
| 65 psi | 4.48 bar | 448 kPa |
| 80 psi | 5.52 bar | 552 kPa |
| 100 psi | 6.89 bar | 689 kPa |
| 120 psi | 8.27 bar | 827 kPa |
The middle of the table is where passenger cars live: most door-jamb placards call for 30 to 36 psi, which is 2.1 to 2.5 bar. The top of the table belongs to road bicycles and light truck tires, and pressures above 120 psi are mostly industrial rather than automotive.
Which unit you will meet where
In the United States, everything is psi: the placard inside the driver's door, the gauge at the gas station, the sidewall maximum molded into the tire. In Europe the same three places read bar, and a rental car's placard may show bar and kPa side by side. Bicycle pumps sold worldwide usually carry both scales on one dial, with bar on the outer ring. Espresso machines are the odd case in American kitchens: their pump gauges read bar everywhere, because the standard 9 bar extraction pressure comes from Italian practice.
Worked examples
A car placard in psi, a pump in bar. Your door jamb says 35 psi. The filling-station pump in France tops out its display in bar: 35 × 0.0689476 = 2.41 bar. Set the pump to 2.4 bar; the missing hundredth is far inside the accuracy of any forecourt gauge.
A European spec in bar, a gauge in psi. A German owner's manual recommends 2.5 bar. Your gauge reads psi: 2.5 × 14.5038 = 36.3 psi. Note that the same car sold in the US would simply have 36 psi printed on its placard — the recommendation did not change, only the label.
Bicycles. A road tire at 100 psi is running 6.89 bar, near the top of most floor-pump gauges. A mountain bike tire at 30 psi is at 2.07 bar — a pressure that looks alarmingly low on a bar gauge if you are used to road numbers, but is exactly right for wide, low-pressure rubber.
Espresso. The classic extraction pressure of 9 bar equals 9 × 14.5038 = 130.5 psi. That is roughly four times a car tire's pressure, which is why espresso boilers are serious pressure vessels despite their size.
Gauge pressure vs. absolute pressure
One subtlety is worth knowing. Tire gauges measure gauge pressure: pressure above the surrounding atmosphere, which at sea level is about 14.7 psi, or 1.01 bar. A flat tire reads zero on a gauge even though the air inside it is at full atmospheric pressure. Because both sides of a tire or pump conversion use gauge pressure, the atmospheric offset cancels and the formulas above apply directly. It only starts to matter in engineering contexts that mix gauge and absolute readings, or at altitude, where atmospheric pressure is lower and a gauge will read slightly differently for the same amount of air.
Whichever scale your gauge uses, measure tires cold — before driving, or at least three hours after. A warm tire reads 2 to 4 psi (about 0.2 bar) high, and correcting a hot reading down to the placard value leaves the tire underinflated once it cools. For the rest of the unit pairs in daily life, the full conversion chart and the calculator cover them in one place.