Millipascals to inches of water converter above calculates how many inches of water are in 'X' millipascals (where 'X' is the number of millipascals to convert to inches of water). In order to convert a value from millipascals to inches of water (from mPa to inH2O) simply type the number of mPa to be converted to inH2O and then click on the 'convert' button.