Bar
The bar is a metric unit of pressure defined as exactly 100 000 pascals, close to (but slightly below) one standard atmosphere.
Symbol: bar
Quantity: pressure, stress and differential pressure (force per unit area)
SI relation: 1 bar = 100000 Pa (exact)
Derivation: 1 bar = 10⁵ Pa (exact, by definition)
Exact: yes, by definition
History
The name comes from the Greek báros, weight. The bar is not part of the SI but remains widely used in Europe and in industry.
Typical uses
- Compressed air and pneumatics (6–8 bar)
- Hydraulic and process equipment ratings (PN10, PN16 = 10, 16 bar)
- Scuba cylinders (200–300 bar)
- Gauge (barg) and absolute (bara) readings
Convert bar to other units
| Conversion | 1 bar equals | Reverse |
|---|---|---|
| bar to pascal | 100000 Pa | pascal to bar |
| bar to kilopascal | 100 kPa | kilopascal to bar |
| bar to psi | 14.50377377 psi | psi to bar |
| bar to millimeter of mercury | 750.0615758 mmHg | millimeter of mercury to bar |
| bar to inch of water | 401.463076 inH₂O | inch of water to bar |
| bar to atmosphere | 0.9869232667 atm | atmosphere to bar |
| bar to megapascal | 0.1 MPa | megapascal to bar |
| bar to millibar | 1000 mbar | millibar to bar |
| bar to torr | 750.0616827 Torr | torr to bar |
| bar to millimeter of water | 10197.16213 mmH₂O | millimeter of water to bar |
| bar to centimeter of water | 1019.716213 cmH₂O | centimeter of water to bar |
| bar to inch of mercury | 29.5299833 inHg | inch of mercury to bar |
| bar to decibar | 10 dbar | decibar to bar |
| bar to inch of water (60 °F) | 401.864652 inH₂O (60 °F) | inch of water (60 °F) to bar |
| bar to barye | 1000000 Ba | barye to bar |
Open the Pressure Converter to convert any value between all units.
Sources
- Guide for the Use of the International System of Units (SI), NIST Special Publication 811, 2008 Edition, National Institute of Standards and Technology , Appendix B.8, "bar".
Last reviewed: . Factors are stored exactly and computed with 50-digit decimal arithmetic. See how we verify conversion factors.
Cite this page
APA
Scientific Converters. (2026, October 15). Bar. Retrieved October 17, 2026, from https://scientificconverters.com/units/bar/
IEEE
Scientific Converters, "Bar," scientificconverters.com. Accessed: Oct. 17, 2026. [Online]. Available: https://scientificconverters.com/units/bar/