Bar (bar)
Definition
Exactly 100 000 pascals (100 kPa), close to one atmosphere.
History
The bar was introduced in the early twentieth century by the meteorologist Vilhelm Bjerknes, defined as exactly 100 000 pascals, close to average sea-level air pressure. Its name comes from the Greek for weight.
Where it is used
The bar is common outside the United States for tyre pressure, diving and weather, where the closely related millibar is also used.
Typical uses include tyre pressure outside the US, diving, weather.
Conversion pages
These pages convert bar to or from another unit in pressure.