Millibars to Atmospheres converter

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

1 mbar ≈ 0.000986923266716 atm
1 atm = 1013.25 mbar

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

Definitions: 1 mbar = 0.001 bar; 1 atm = 101325 Pa

The millibar (mbar) is one thousandth of a bar and equals exactly one hectopascal. It is the traditional unit for atmospheric pressure in meteorology and aviation, and it is common for vacuum pressures.

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.