Convert hectopascals to millimeters of mercury

Explanation

From this page you can convert hectopascals to millimeters of mercury (or hPa to mmHg) simply, by using the application above.

In case you are wondering, to convert from hectopascals to millimeters of mercury you need to multiply by 0.7501. This factor is calculated using the respective definitions of the two units you can find below.

Formula

1 hPa≈0.7501 mmHg

hectopascalshPa

dimension	pressure
system	International system of units (SI)
symbol	hPa

The hectopascal (hPa) is a unit of pressure.

One hectopascal is equal to a millibar, this explains why this unit is used in meteorology for atmospheric pressure when integer powers of 1000 are prefered in almost all other fields of science.

Definition of the hectopascal

One hectopascal is equal to 100 pascals.

Equivalences

One hectopascal is equivalent to:

Prefix

hecto

10²

The prefix hecto- comes from the Greek hekatón meaning a hundred. The associated multiplicative factor is 100 or 10².

Pressure units

nanopascal	nPa	0.000 000 001
micropascal	µPa	0.000 001
millipascal	mPa	0.001
centipascal	cPa	0.01
decipascal	dPa	0.1
pascal	Pa	1
dekapascal	daPa	10
hectopascal	hPa	100
kilopascal	kPa	1000
megapascal	MPa	1 000 000
gigapascal	GPa	1 000 000 000

The International System of Units

The International System of Units or SI (from the French Système international (d'unité)), also called metric system in the U.S., is a coherent system of units that was published 1960. It is official in nearly every country.

The General Conference on Weights and Measures (Conférence générale des poids et mesures) is tasked with overseeing the SI.

Related Conversions

millimeters of mercurymmHg

dimension	pressure
symbol	mmHg

The conventional millimeter of mercury (mmHg) is a unit of pressure.

Definition of the millimeter of mercury

The conventional millimeter of mercury is defined using a value for the density of mercury of 13595.1 kg/m³ and the standard gravity.

Value in terms of the SI

One millimeter of mercury is 133.3224 pascals. This is an approximation.

NIST Guide to the SI, Appendix B.9

History

The most simple barometer is made of a vertical glass tube from which all air as been removed, with a sealed top and an open base submerged into mercury. The atmospheric pressure then pushes the mercury up the tube until it equalize with the pressure at the base of the column of mercury.

The pressure is then expressed as the height of the column of mercury in millimeters.

The measure is dependent on the temperature and local gravity. To ease conversion between units, the millimeter of mercury has been defined with these parameters respectively fixed to approximately 0 °C and exactly 9.80665 m/s².

Metric mercury units

millimeter of mercury	mmHg	1
centimeter of mercury	cmHg	10
centimeter of mercury at 0 °C	-