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To convert from millimeter of mercury (mmHg) to meter of water @ 4°C (mH2O), use the following formula:
meter of water @ 4°C (mH2O)
= 0.133322 × 19.80665× millimeter of mercury (mmHg)
= 0.013595060494664334916× millimeter of mercury (mmHg)
Let's convert 5 millimeter of mercury (mmHg) to meter of water @ 4°C (mH2O).
Using the formula:
5 × 0.013595060494664334916 = 0.06797530247332167458
Therefore, 5 millimeter of mercury (mmHg) is equal to 0.06797530247332167458 meter of water @ 4°C (mH2O).
How many millimeters of mercury are in one meter of water @ 4°c? One meter of water @ 4°C (mH2O) contains 73.556127270818019532 millimeters of mercury (mmHg) — the inverse of the factor above. Multiplying by 0.013595060494664334916 takes you from millimeters of mercury to meters of water @ 4°c; multiplying by 73.556127270818019532 brings you back.
Put in words: one millimeter of mercury equals 0.013595060494664334916 meters of water @ 4°c, so the millimeter of mercury is the smaller unit of this pair. Converting between them never changes the amount of pressure being measured — only the size of the unit you count it in.
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:
A meter of water @ 4°C (mH2O) is a metric unit used to measure pressure.
It is precisely defined as 9.80665 kilopascals (kPa).
The specific temperature of 4°C (39.2°F) is key because this is the point where pure water is at its heaviest or most dense (approximately 999.972 kg/m3).
Using this temperature provides a stable and reliable standard for defining pressure.
This precision is essential in scientific and engineering fields like hydraulics and fluid mechanics, ensuring that measurements of pressure head are consistent and accurate across different applications and locations.
The unit "meter of water" (mH2O) is frequently used in civil engineering, hydrology, and irrigation to measure water levels and pressure.
It provides an intuitive way to express the pressure exerted by a column of water, such as the water level in a reservoir, dam, or groundwater well. This measurement is sometimes referred to as the 'piezometric head'.
It is also commonly used to specify the performance of pumps, indicating the height to which a pump can lift water.
For practical use, it's often helpful to know how mH2O converts to other common pressure units.
One mH2O is equal to:
These conversion factors allow engineers and scientists to easily translate pressure specifications between different international and imperial systems.
Here are some quick reference conversions from millimeter of mercury (mmHg) to meter of water @ 4°C (mH2O):
| millimeters of mercury | meters of water @ 4°C |
|---|---|
| 0.000001 mmHg | 1.3595060494664334916× 10-8 mH2O |
| 0.001 mmHg | 0.000013595060494664334916 mH2O |
| 0.1 mmHg | 0.0013595060494664334916 mH2O |
| 1 mmHg | 0.013595060494664334916 mH2O |
| 2 mmHg | 0.027190120989328669832 mH2O |
| 3 mmHg | 0.040785181483993004748 mH2O |
| 4 mmHg | 0.054380241978657339664 mH2O |
| 5 mmHg | 0.06797530247332167458 mH2O |
| 6 mmHg | 0.081570362967986009496 mH2O |
| 7 mmHg | 0.095165423462650344412 mH2O |
| 8 mmHg | 0.10876048395731467933 mH2O |
| 9 mmHg | 0.12235554445197901424 mH2O |
| 10 mmHg | 0.13595060494664334916 mH2O |
| 20 mmHg | 0.27190120989328669832 mH2O |
| 30 mmHg | 0.40785181483993004748 mH2O |
| 40 mmHg | 0.54380241978657339664 mH2O |
| 50 mmHg | 0.6797530247332167458 mH2O |
| 100 mmHg | 1.3595060494664334916 mH2O |
| 1000 mmHg | 13.595060494664334916 mH2O |
| 10000 mmHg | 135.95060494664334916 mH2O |
For all Pressure converters, choose units using the From/To dropdowns above.