Millibars to millimeters of mercury converter above calculates how many millimeters of mercury are in 'X' millibars (where 'X' is the number of millibars to convert to millimeters of mercury). In order to convert a value from millibars to millimeters of mercury (from mbar to mmHg) type the number of mbar to be converted to mmHg and then click on the 'convert' button.