Pressure unit conversions Enter a value and the original unit to be converted, and then click on the "Calculation" button for converted values by unit. Enter a value. mega pascal(MPa) atmospheric pressure(atm) kilo pascal(kPa) meter of mercury column(mHg) hecto pascal(hPa) inch of mercury column(inHg) kilogram force/square centimeter(kgf/cm2) meter of water column(mH2O) foot of water column(ftH2O) pound force/square inch(lbf/in2) *Whenever you change values, be sure to click on the"Calculate"button.