1 bar equals exactly
1.000 mbar
The millibar (mbar) is a submultiple of the bar, and is the unit historically used in meteorology to report atmospheric pressure, although today it is numerically identical to the hectopascal (hPa), the officially recommended unit. One bar contains exactly 1,000 millibars.
To convert a measurement from bar to millibar, simply multiply the value by 1,000:
To convert from millibar to bar, perform the inverse operation, dividing by 1,000:
The millibar is still today the most used unit in weather reports to report sea-level atmospheric pressure, especially on synoptic maps and weather forecasts, where values like '1013 mbar' indicate normal pressure conditions.