Centimeter of water

The centimeter of water (cmH2O) is a unit of pressure commonly used in medical and fluid dynamics contexts to measure small pressures, particularly in fields where precision and sensitivity are critical. It's particularly useful in describing fluid pressure in biological systems.

Definition and Usage

The centimeter of water is defined as the pressure exerted by a column of water one centimeter in height at the standard acceleration due to gravity. It is often used in medical settings to measure physiological pressures.

Significance in Medical and Fluid Dynamics

The centimeter of water finds its importance in various fields:

  • Medical Applications: It's used to measure pressures in blood vessels, respiratory systems, and other biological systems.
  • Fluid Dynamics: Engineers and researchers use it to study fluid behavior in small-scale systems.
  • Hydrology: It's used to measure and discuss water pressure in shallow systems.

Conversions and Equivalents

Understanding conversions of centimeter of water to other pressure units is valuable:

  • 1 Centimeter of Water (cmH2O) = 98.0665 Pascal (Pa)
  • 1 Centimeter of Water (cmH2O) ≈ 0.980665 mbar
  • 1 Centimeter of Water (cmH2O) ≈ 0.00096784 bar
  • 1 Centimeter of Water (cmH2O) ≈ 0.014223 psi

Medical and Biological Relevance

Centimeter of water is widely used in medical settings:

  • Respiratory Pressure: It's used to measure pressure changes in the lungs and respiratory system.
  • Cardiovascular Systems: Centimeter of water measures blood pressure in various vessels.
  • Fluid Balance: It's used to assess fluid pressures in biological systems.


The centimeter of water (cmH2O) is a specialized unit of pressure with significant applications in medical and fluid dynamics contexts. Its precision and sensitivity make it particularly useful for measuring pressures in biological systems and small-scale fluid dynamics experiments.

Keywords: Centimeter of Water, cmH2O, pressure unit, medical applications, fluid dynamics, conversions