Inches of water to kilopascals converter on this page calculates how many kilopascals are in 'X' inches of water (where 'X' is the number of inches of water to convert to kilopascals). In order to convert a value from inches of water to kilopascals (from inH2O to kPa) type the number of inH2O to be converted to kPa and then click on the 'convert' button.