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