Conversion Result
What is Pressure Unit Conversion?
Pressure unit conversion is the process of changing the reference system (unit) expressing a physical quantity (in this case, pressure) to a value in a different reference system.
Definition of Pressure (P): Pressure is defined as the force (F) acting per unit area (A).
P = F / A
Based on this fundamental definition, various units have arisen, and each unit is used differently depending on the measurement system or historical background.
How to Use the Pressure Unit Converter
The pressure unit converter can generally be used easily and intuitively in three steps.
1. Select the unit to convert from (Source Unit): Select the unit of the pressure value you currently know (e.g., bar)
2. Enter the value to convert: Input the numerical value of the pressure you want to convert (e.g., 1.5)
3. Select the unit to check the result: Select the unit you want the converted result in (e.g., psi).→ Result Check: The converter automatically calculates the input value (1.5 bar) into the selected unit (psi) and immediately displays the result (e.g., 1.5 bar ≈ 21.756 psi).
Frequently asked questions (FAQs)
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Can conversion errors occur in the converter?
The converter's calculation uses precise mathematical conversion constants, so there is almost no inherent error.
However, minor rounding errors may occur in the displayed value depending on how many decimal places the result is expressed to.
Generally, it provides sufficient precision for engineering purposes. -
What are the most common pressure units supported by the converter?
Most converters support the international standard unit Pa (Pascal) and its multiples (kPa, MPa), as well as commonly used units in daily life and industry such as bar, atm (standard atmosphere), psi (pounds per square inch), kgf/cm2, and mmHg (Torr).
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Why are there so many pressure units?
Pressure units have evolved based on the measurement environment and historical background.
For example, mmHg originated from measuring the height of a mercury column, and atm was defined based on the Earth's atmospheric pressure.
Various units are used based on the convenience and tradition of each field. -
Can absolute pressure and gauge pressure also be converted?
The pressure unit converter only converts the magnitude of the value.
Gauge pressure is measured with the atmosphere as the zero reference, and absolute pressure is measured with a perfect vacuum as the zero reference.
The process of converting gauge pressure to absolute pressure (Gauge Pressure + Atmospheric Pressure) or vice versa is required before using the converter, and the user must manually add or subtract the reference atmospheric pressure value. -
Can vacuum pressure (negative pressure) also be converted?
Yes, you can. You just need to input a negative (-) value into the pressure unit converter.
When using units like Torr or mmHg that indicate vacuum, the value can be converted to an absolute pressure value referenced to a perfect vacuum (0).
Conversion units and descriptions
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Pascal (Pa)
Pascal (Pa) is the SI derived unit of pressure, meaning the pressure when a force of 1 N is uniformly applied over an area of 1 m².
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Kilopascal (kPa)
Kilopascal (kPa) is an SI derived unit of pressure representing the pressure when a force of 1,000 Newtons is applied over one square meter.
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Megapascal (MPa)
Megapascal (MPa) is a pressure unit equivalent to 1,000,000 Pascals (Pa), primarily used in materials science for material compressive strength or tensile strength.
It is also commonly utilized in various industrial settings, such as high-pressure gas filling and fire hoses, to measure or express pressure. -
Bar (bar)
The pressure unit bar is equivalent to 100,000 Pascals (Pa) per square meter, widely used internationally and similar in magnitude to atmospheric pressure (1 atm).
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Millibar (mbar)
Millibar (mbar) is 1/1,000th of one atmosphere (standard atmosphere), where 1 mbar = 100 Pascals (Pa) = 1 hectopascal (hPa).
SI Unit System and Pascal-Based
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Standard Atmosphere (atm)
Standard Atmosphere refers to 1 atmosphere (101,325 Pa) or 760 mmHg, based on the average atmospheric pressure at sea level.
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Technical Atmosphere (at)
Technical Atmosphere refers to the three main concepts categorized by the type and reference point of pressure: gauge pressure, absolute pressure, and atmospheric pressure.
Atmospheric Pressure-Based
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Millimeter of Mercury (mmHg)
Millimeter of mercury (mmHg) is a unit representing the pressure exerted by a 1 mm high column of mercury, and it was one of the early standard units of atmospheric pressure.
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Torr (Torr)
Torr is a pressure unit based on the height of a mercury column, where 1 Torr is approximately equal to 133.322 Pascals (Pa).
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Millimeter of Water (mmH₂O)
A unit expressing pressure using the height of a column of water. 1 mmH2O means a force of 9.80665 kPa (kilopascals) acting vertically on an area of 1 square centimeter (1 cm2).
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Inch of Water (inH₂O)
A unit expressing pressure by the height of water. 1 inch H2O is equal to the pressure exerted by a 1-inch high column of water on an area of 1 square inch.
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Inch of Mercury (inHg)
A unit representing the pressure exerted by a 1 millimeter high column of mercury, mainly used in medicine and meteorology. (Note: The provided Korean description for inch of mercury seems to have confused mm with inch. The English conversion reflects the typical usage of 'inch of mercury' as a manometric unit.)
Fluid Column Based (Liquid Column Height)
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Pounds per Square Inch (psi)
Pounds per square inch (PSI) is the unit of pressure exerted when a force of 1 pound-force is applied vertically over an area of 1 square inch.
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Kilopound per Square Inch (ksi)
Kilopound per square inch (ksi) is an American unit representing the pressure when a force of 1,000 pounds (1,000 lb) is applied vertically over an area of 1 square inch (1 in2).
🇺🇸 Imperial/US Customary System Based