Pressure ConverterConverters
psi, bar, Pa, kPa, atm, mmHg, inHg, and torr.
How to convert tire pressure from psi to bar and kPa
The label in your car door may say 2.3 bar while the pump at the station shows psi. Convert the number once, write it down, and fill the tires to the same value every time.
Why the units trip people up at the pump
Tire pressure is printed in whatever unit the car's market and the gauge maker chose. A door label might say 2.2 bar or 220 kPa, the air pump shows psi, and a bike tire lists both. A typical car tire is around 32 psi, which is about 2.2 bar. Set a pump to 32 while it reads in bar and the tire is far over any safe value. Set it to 2.2 while it reads in psi and the tire is nearly empty.
Weather data and engineering specs add a second trap. A tire gauge shows the pressure above the surrounding air, called gauge pressure. A barometer shows the total pressure, called absolute pressure. At sea level the two differ by about 1 atm, which is 101.325 kPa, so adding or forgetting that offset gives a number that is far off.
Convert the value and check it against the label
The Pressure Converter changes a value between psi, bar, kPa, atm, Pa, mbar, mmHg, inHg, and Torr as you type, and lists the value in every unit at once. It uses 1 psi = 6,894.757 Pa and 1 bar = 100,000 Pa, so 32 psi is 2.206 bar and 1 bar is 14.503774 psi. For common tire values, 30 psi is 2.07 bar, 33 psi is 2.28 bar, 35 psi is 2.41 bar, and 36 psi is 2.48 bar. Car tires are usually 30 to 35 psi, about 2.1 to 2.4 bar, but the figure for your car is on the label inside the driver's door. The converter changes units only. It doesn't turn a gauge reading into an absolute one or back.
Fill your tires to the right pressure in any unit
- Find the recommended pressure on the label inside the driver's door and note its unit.
- Type the value into the Pressure Converter, choose the label's unit under From and the pump's unit under To.
- Round the result to what the pump can show, for example 2.2 bar or 32 psi, and write it down.
- Fill or release air until the pump's gauge shows that value.
What a unit converter can't tell you
- It changes units only, not between gauge and absolute pressure.
- The right pressure for your car comes from the door label or the manual, not from a typical range.
- mmHg and inHg use the conventional values at 0 °C and standard gravity.
Frequently asked questions
What is 32 psi in bar?
About 2.21 bar, or 2.206 to three decimals.
How do I convert psi to bar?
Multiply by 0.0689476, or divide by 14.5038.
What is 2.5 bar in psi?
36.26 psi.
Does a tire gauge show gauge or absolute pressure?
Gauge pressure, the pressure above the surrounding air. Absolute pressure is about 1 atm higher at sea level.
Related tools
Tools used in this guide
