Centimeters of water to kilopascals conversion calculator shown above calculates how many kilopascals are in 'X' centimeters of water (where 'X' is the number of centimeters of water to convert to kilopascals). In order to convert a value from centimeters of water to kilopascals (from cmH2O to kPa) type the number of cmH2O to be converted to kPa and then click on the 'convert' button.