Atmosphere (atm)
Definition
The standard atmosphere, exactly 101 325 pascals.
History
The standard atmosphere was defined as a reference pressure of exactly 101 325 pascals, close to average pressure at sea level. It gave a convenient benchmark before the pascal became standard.
Where it is used
Atmospheres are used in diving, chemistry and when describing pressure at altitude.
Typical uses include diving, chemistry, altitude.
Conversion pages
These pages convert atmosphere to or from another unit in pressure.