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Single conversion
To convert from millimeter of mercury (mmHg) to bar (bar), use the following formula:
Let's convert 5 millimeter of mercury (mmHg) to bar (bar).
Using the formula:
Therefore, 5 millimeter of mercury (mmHg) is equal to bar (bar).
Here are some quick reference conversions from millimeter of mercury (mmHg) to bar (bar):
| millimeters of mercury | bar |
|---|---|
| 0.000001 mmHg | bar |
| 0.001 mmHg | bar |
| 0.1 mmHg | bar |
| 1 mmHg | bar |
| 2 mmHg | bar |
| 3 mmHg | bar |
| 4 mmHg | bar |
| 5 mmHg | bar |
| 6 mmHg | bar |
| 7 mmHg | bar |
| 8 mmHg | bar |
| 9 mmHg | bar |
| 10 mmHg | bar |
| 20 mmHg | bar |
| 30 mmHg | bar |
| 40 mmHg | bar |
| 50 mmHg | bar |
| 100 mmHg | bar |
| 1000 mmHg | bar |
| 10000 mmHg | bar |
For all Pressure converters, choose units using the From/To dropdowns above.
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:
The bar is a metric unit of pressure.
It is defined as exactly 100 kilopascals (kPa), or 100,000 Pascals (Pa).
Although it is not an official part of the International System of Units (SI), it is widely accepted for use with the SI. The bar is a popular unit for measuring pressure because it is very close to the average atmospheric pressure on Earth at sea level.
The term "bar" comes from the Greek word βάρος (baros), which means "weight."
The unit was introduced by British meteorologist William Napier Shaw in 1909. It is still widely used in meteorology, oceanography, and engineering.
A common point of confusion is the difference between a bar and a standard atmosphere (atm).
While they are very close in value, they are not the same:
This means 1 bar is approximately equal to 0.987 atm. Because it's so close to atmospheric pressure and is a round number (100 kPa), the bar is a very convenient unit for many applications.
The bar is a versatile unit used to measure pressure in many industrial and everyday contexts.
Common examples include: