The Millimeter of water

• The millimeter of water (mmH2O) is defined as the pressure exerted at the base of a column of fluid exactly 1 millimeter (mm) high
• The fluid density is exactly 1.004514556 gram per cubic centimeter (g/cm³), at a physical location where the gravity acceleration is exactly 9.80665 m/sec²

1 millimeter of water = 9.806648601 × 10^-5 bar

1 mmH2O = 9.806648601 × 10^-6 MPa

1 mmH2O = 9.80664857 Pa