Millibar (mbar)
The millibar is one thousandth of a bar and is often used in meteorology for atmospheric pressure.
History: the millibar became popular in meteorology because atmospheric pressure is conveniently near 1000 mbar.
Quickly convert millibars to atmospheres without lookup tables or manual math.
This page is focused on converting millibars to atmospheres. Type a number into the first field and the result appears immediately in the second field.
Example: 1 mbar = 0.0009869233 atm. Conversion formula: result = value × 100 / 101325.
Use this converter for everyday calculations, study notes, engineering checks, and quick value verification without installing a separate app.
The millibar is one thousandth of a bar and is often used in meteorology for atmospheric pressure.
History: the millibar became popular in meteorology because atmospheric pressure is conveniently near 1000 mbar.
The atmosphere reflects approximate air pressure at sea level and is used as a practical pressure measure.
History: the standard atmosphere began as an approximation of mean air pressure at sea level.
Enter a value in the Millibar field. The converter applies the formula "result = value × 100 / 101325" and immediately shows the result in atmospheres.
1 mbar = 0.0009869233 atm.
Yes. Use the swap button or choose the reverse pair from the full conversion list.