Millimeters Of Mercury to Kilopascals (mmHg to kPa)

1 millimeter of mercury equals 0.1333223874 kilopascals (rounded).

1 millimeter of mercury = 0.1333223874 kilopascals

How to convert millimeters of mercury to kilopascals

To convert millimeters of mercury to kilopascals, multiply the number of millimeters of mercury by 0.1333223874. The factor is rounded to 10 significant digits. To go the other way, multiply kilopascals by 7.500615758 (rounded).

kilopascals = millimeters of mercury × 0.1333223874

Example: 10 millimeters of mercury = 1.333223874 kilopascals.

About these units

Millimeter Of Mercury (mmHg)

ScientificCurrent unit

About 133.322 pascals, the pressure from a 1 mm column of mercury. Blood pressure is still reported in mmHg.

Where the torr honors a person, the millimeter of mercury describes a gauge. It is a manometric unit: originally the pressure from a mercury column 1 mm tall, which means it depends on an assumed fluid density and on gravity. Mercury manometers were among the first accurate pressure gauges, and 17th-century experiments by Torricelli and then Pascal, whose mercury stood at about 23 inches on a mountaintop against about 26 at its base, showed that air has weight and that pressure drops with altitude.

To remove the ambiguity, mmHg is now fixed at exactly 133.322387415 Pa, using a conventional mercury density of 13,595.1 kg per cubic meter and standard gravity. The torr, defined as one 760th of a standard atmosphere, differs from it by only about 0.000015 percent.

Mercury is toxic and its readings vary with temperature and local gravity, so mercury gauges are now used less, and the unit's use is discouraged. Medicine nonetheless keeps it, especially for blood pressure, which is reported relative to atmospheric pressure, and hypertension guidelines in the US and Europe still use it.

1 millimeter of mercury = 133.3223874 pascals (approximately).

Sources: Wikipedia: Millimetre of mercury; Wikipedia: Torr; Wikipedia: Blaise Pascal

Kilopascal (kPa)

Metric (SI)Current unit

1,000 pascals. Used for tire pressures, weather reports in many countries and engineering.

Kilopascal is the form of the pascal that most people actually use. The pascal itself is very small, so outside meteorology the kilopascal became the common choice in most fields, and it equals one centibar. Medical elastography reports tissue stiffness in kPa, and Canada reports atmospheric pressure in kPa rather than hectopascals.

A standard atmosphere is 101.325 kPa. In 1982 IUPAC recommended a different reference for chemistry, a standard pressure of exactly 100 kPa, which split the older convention of 1 atm into two competing standards.

Blood pressure shows how the units line up. One mmHg is 0.13332 kPa, and a normal reading is below about 16.0 kPa systolic and 10.7 kPa diastolic, the same thing as the familiar 120 over 80 in millimeters of mercury.

1 kilopascal = 1,000 pascals (exactly).

Sources: Wikipedia: Pascal (unit); Wikipedia: Standard atmosphere (unit); Wikipedia: Millimetre of mercury

Related conversions

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