Pressure Converter
One bar equals 14.5038 PSI and 100,000 pascals, and one PSI is 6,894.76 pascals or 0.0689 bar. One standard atmosphere is 101,325 Pa, 1.01325 bar or 14.696 PSI. This pressure converter switches between Pa, kPa, bar, PSI, atm and mmHg as you type.
1 psi = 0.06894757 bar
How to use the Pressure Converter
- Type a pressure in the From box. It starts at 32 PSI, a typical car tire.
- Choose the From and To units, for example PSI and bar.
- Read the result in the To box, or type there to convert the other way.
- Use the swap button to reverse the units, and the chips to see the reading in every other unit.
Formula
result = value × (from-unit in Pa) ÷ (to-unit in Pa)All units convert through pascals: 1 kPa = 1,000 Pa, 1 bar = 100,000 Pa, 1 psi = 6,894.757 Pa, 1 atm = 101,325 Pa and 1 mmHg = 133.322 Pa (1 mmHg is effectively equal to 1 torr).
Common pressure conversions
- 1 bar = 14.5038 psi = 100 kPa
- 1 psi = 0.0689476 bar = 6.89476 kPa
- 1 atm = 101.325 kPa = 14.696 psi = 760 mmHg
- 32 psi = 2.21 bar = 220.6 kPa
- 2.5 bar = 36.3 psi
Where each unit is used
- PSI: tire pressure and hydraulics in the US
- Bar and kPa: tire pressure, diving and engineering in most other countries
- Pascals: the SI unit, used in science and weather (hectopascals)
- Atmospheres: chemistry and diving depth
- mmHg (torr): blood pressure and vacuum systems
Gauge and absolute pressure
Tire gauges and most industrial gauges read gauge pressure, the pressure above the surrounding atmosphere. Absolute pressure adds atmospheric pressure, about 1.013 bar or 14.7 psi at sea level. Convert like with like: a gauge reading converts to a gauge value in the other unit.
Pressure Converter questions
How do I convert tire pressure from PSI to bar?
Divide PSI by 14.504 to get bar. For example, 32 psi is about 2.21 bar and 35 psi is 2.41 bar. Multiply bar by 14.504 to go back. European cars usually list tire pressure in bar, while US cars use psi. Both are gauge pressures.
What is the difference between PSI and bar?
Both measure pressure; they are just different units. One bar is 14.504 psi, roughly the air pressure at sea level. PSI (pounds per square inch) is common in the US, while bar and kilopascals are standard in most other countries.
How many kPa are in a PSI?
One psi is 6.895 kilopascals, and one kPa is 0.145 psi. Canadian and Australian tire placards often show kPa, so 220 kPa is about 32 psi. To convert kPa to bar, divide by 100. Weather maps use hectopascals: 1,013 hPa is standard sea-level pressure, which equals 101.3 kPa or 14.7 psi. One bar is exactly 100 kPa.
What is the difference between gauge and absolute pressure?
Gauge pressure is measured relative to the surrounding air, while absolute pressure includes atmospheric pressure. At sea level, absolute pressure is gauge pressure plus about 14.7 psi (1.013 bar). Tire and compression readings are gauge values; vacuum and weather readings are absolute.
Should I use PSI or pascals for engine compression testing?
Use psi or bar, because pascals give unwieldy numbers in the millions. Healthy gasoline engines typically read about 120 to 200 psi (8 to 14 bar), and diesels about 300 to 500 psi. Always compare with the manufacturer specification for your engine.
What units do hydraulic systems use?
Industrial hydraulics are usually specified in bar or psi; many systems run between 100 and 400 bar (1,450 to 5,800 psi). Choose components rated comfortably above the maximum operating pressure, and keep one unit throughout your documentation. Mixing units in a specification is a common source of costly ordering mistakes.
How do mmHg and torr relate to other pressure units?
One mmHg is 133.322 Pa and is practically equal to one torr. Standard atmospheric pressure is 760 mmHg. Blood pressure is measured in mmHg, so 120 mmHg is about 16 kPa or 2.32 psi above atmospheric pressure. Vacuum gauges also often read in torr or mbar.