Hectopascals to Atmospheres converter

To convert hectopascals to atmospheres, enter the value in the first field. The result in atmospheres is calculated automatically using the exact conversion factor.

1 hPa ≈ 0.000986923266716 atm
1 atm = 1013.25 hPa

Formula: atm ≈ hPa × 0.000986923266716
hPa = atm × 1013.25

Definitions: 1 hPa = 100 Pa; 1 atm = 101325 Pa

The hectopascal (hPa) equals 100 pascals and is exactly the same as one millibar. It is the unit weather services use for atmospheric pressure, with average sea-level pressure around 1013 hPa.

The standard atmosphere (atm) is exactly 101,325 pascals, the average air pressure at sea level. It is a reference pressure in chemistry and physics and is used to express high pressures as multiples of atmospheric pressure.

See the conversion table with commonly used values, handy for quick reference or study.