A centimeter (centimetre) of water or cmH₂O is a somewhat outdated unit for pressure. It is used to measure the central venous pressure, the intracranial pressure while sampling cerebrospinal fluid, as well as determining pressures during mechanical ventilation or in water supply networks (then usually in metres water column).

It is defined as the pressure exerted by a column of water of 1 cm in height at 4 °C (temperature of maximum density) at the standard acceleration of gravity.

1 cmH₂O = 98.0638 pascals

To convert this measure to other units, the following conversion is used:

1 mmHg = 1.36 cmH₂O = 0.133 kPa = 0.0193 psi = 1.3332 mbar

External links

• Pressure conversion calculator at Cornell University website

Units of pressure