Formula
The pascal definition of the pound per square inch fixes the factor:
kPa = psi × 6.894757293
Bar is that result divided by 100. The page starts from psi because that is the marking on many passenger-car placards.
Assumptions
- The pressure is gauge pressure as marked, not a scientific absolute pressure.
- The factor uses 1 psi = 6,894.757293 Pa.
- No temperature compensation is applied.
Worked example
32 psi is 2.21 bar, or 220.63 kPa.
Input definitions
- psi
- Pounds per square inch, the unit on many door-jamb placards.
- Bar
- 100 kilopascals. A common marking on European placards.
Limitations
This uses the nominal size, not a mounted measurement. Confirm the load index, speed rating, and clearance before the tire is installed.
Questions
Is 1 bar exactly 14.5 psi?
Nearly. One bar is about 14.5038 psi. This page uses the pascal definition rather than a rounded 14.5.
Does this set the recommended pressure?
No. It converts the number you type. The placard, not this page, chooses the pressure.