Pressure Conversion Calculator Pressure Conversion Calculator,Pressure Conversion,Pressure Unit Converter online free pascal (Pa) bar (bar) kilopascal (kPa) hectopascal (hPa) millibar (mbar) atmosphere-standard (atm) mm of mercury (mmHg) pound per ft² (lb/ft²)2 pound per in² (lb/in² or psi)2 in of water (39.2 °F) (inH20) kgf/cm2 kgf/m2 mm of water (3.98 °C) Pressure Conversion Calculator will convert pressure values to ten different standard units for pressure.