Centimeters of mercury to kilopascals conversion calculator above calculates how many kilopascals are in 'X' centimeters of mercury (where 'X' is the number of centimeters of mercury to convert to kilopascals). In order to convert a value from centimeters of mercury to kilopascals (from cmHg to kPa) just type the number of cmHg to be converted to kPa and then click on the 'convert' button.