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