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Multiple conversions
To convert from millimeter of mercury (mmHg) to pascal (Pa), use the following formula:
To convert from millimeter of mercury (mmHg) to kilopascal (kPa), use the following formula:
To convert from millimeter of mercury (mmHg) to megapascal (MPa), use the following formula:
To convert from millimeter of mercury (mmHg) to hectopascal (hPa), use the following formula:
To convert from millimeter of mercury (mmHg) to millibar (mbar), use the following formula:
To convert from millimeter of mercury (mmHg) to bar (bar), use the following formula:
Performing a unit conversion between these two measurements is one of the simplest tasks in physics.
Because the Torr is a unit of pressure historically defined to be identical to the millimeter of mercury, the relationship between these two unit symbols (mmHg and Torr) is essentially one-to-one.
The unit is named in honor of Evangelista Torricelli, a renowned Italian physicist and mathematician who invented the barometer. While modern re-definitions have introduced a microscopic difference (where 1 mmHg is technically 0.999997 Torr), for all general applications, you can treat them as equal when you convert mmhg to torr.
For most practical purposes, the mmhg to torr conversion formula is:
Let's say you have a standard atmospheric pressure reading of 760 mmHg and need to express it in Torr.
The value remains the same, making the conversion instant and easy.
To convert from millimeter of mercury (mmHg) to meter of water @ 4°C (mH2O), use the following formula:
To convert from millimeter of mercury (mmHg) to pound per square inch (psi), use the following formula:
With is the ratio between the base units kilopound per square inch (ksi) and kilopascal (kPa).
To convert from millimeter of mercury (mmHg) to kilopound per square inch (ksi), use the following formula:
With is the ratio between the base units kilopound per square inch (ksi) and kilopascal (kPa).
To convert from millimeter of mercury (mmHg) to Inch of mercury (inHg), use the following formula:
With is the ratio between the base units kilopound per square inch (ksi) and kilopascal (kPa).
A millimeter of mercury (mmHg) is a manometric unit of pressure.
It was historically defined as the pressure generated by a column of mercury exactly one millimeter high.
Today, it is most famous as the unit used in medicine for measuring blood pressure. It is also commonly used in meteorology, aviation, and physics to measure atmospheric pressure or vacuum pressure.
The mmHg unit originates from the invention of the barometer by Evangelista Torricelli in 1643.
Torricelli's device measured atmospheric pressure by seeing how high it could support a column of mercury in a tube.
Standard atmospheric pressure was found to support a column approximately 760 mm high, which established 760 mmHg as a standard reference point.
The most well-known application of mmHg is in medicine.
Blood Pressure: Readings are given as two numbers: systolic pressure (when the heart beats) over diastolic pressure (when the heart rests), such as 120/80 mmHg. This is a critical vital sign for human health.
Meteorology: Used for reporting barometric (atmospheric) pressure, which helps in weather forecasting.
Physics & Engineering: Used for measuring vacuum pressures and other low-pressure systems where precision is needed.
While mmHg is common, other pressure units are standard in different fields. Here are the most common conversions: