How to Go From CM to MMHG

Early barometers measured pressure using columns of mercury.
••• Photos.com/Photos.com/Getty Images

Meteorologists and scientists use a variety of methods to describe pressure. One common unit of reporting pressure is centimeters (cm) of water and another is millimeters (mm) of mercury. Units of mm mercury are often abbreviated mm Hg since "Hg" is the chemical symbol for mercury. These units date back to early methods of measuring pressure and describe the height of a column of water or mercury that a given air pressure could support. Normal atmospheric pressure, for example, is 760 mm Hg. You can convert from cm water to mm Hg using a basic mathematical operation.

    Enter the value of pressure, in units of centimeters (cm) water, into the calculator. For example, if your pressure reading was 500 cm water, you would enter 500.

    Divide the value you just entered by 1.36. This number is a conversion factor based on the relative densities of water and mercury and also the difference between centimeters and millimeters. In the example, you would calculate 500/1.36 = 368.

    Report the result of your calculation as the pressure reading in units of millimeters (mm) mercury (Hg).The pressure reading for the example would be 368 mm Hg.

    Tips

    • You can also convert the other way from mm Hg to cm water by multiplying by 1.36.

Related Articles

How to Calculate Pressure Potential
How to Find Relative Barometric Pressure
How to Convert mm Hg to in Hg
How to Calculate PSI
How to Calculate Pressure Potential
How to Calculate GPM from PSI for Water
How to Convert KPS to PSI
How to Convert Milligrams to Fluid Ounces
How to Convert UG/mL to PPM
How to Calculate Temperature From BTU
How to Calculate Water Depth
How to Convert Fluid Ounces of Water to Weight
How to Convert Kilopascals to Joules
How to Calculate Volume of a Rectangular Prism
How to Use Water Displacement to Calculate Volume
How to Convert mmHg to a kPa
How to Calculate Pounds Per Square Inch in Elevated...
Why Does Water Pressure Increase With Depth?
How to Convert Lbs/Mmscf to Ppm
How to Convert PSI to PSIG

Dont Go!

We Have More Great Sciencing Articles!