Pressure converter
Pascals, bars, psi, atmospheres, mmHg and torr with exact factors, and the difference between absolute and gauge values.
Result
100 kPa
- Formula
- 1 bar = 100 kPa
Calculation, assumptions and sources
OverviewConversion of a pressure between pascal, hectopascal, kilopascal, megapascal, bar, millibar, atmosphere, millimetre of mercury, torr and psi.
Conversion of a pressure between pascal, hectopascal, kilopascal, megapascal, bar, millibar, atmosphere, millimetre of mercury, torr and psi. The factors are exact by definition, and the conversion is reversible up to display rounding.
Method & formulasp = F / A
The hPa is used in meteorology, the kPa and MPa in mechanics; the bar and the psi are inherited units. Each conversion is a multiplication by a fixed factor.
- Pa
- Pascal (Pa)
- hPa
- Hectopascal (hPa)
- kPa
- Kilopascal (kPa)
- MPa
- Megapascal (MPa)
- bar
- Bar
- mbar
- Millibar (mbar)
- atm
- Atmosphere (atm)
- mmHg
- Millimeter of mercury (mmHg)
- Torr
- Torr
- psi
- Pound per square inch (psi)
The torr is defined as 1/760 of a standard atmosphere, that is 101,325/760 ≈ 133.322368 Pa. The conventional millimetre of mercury, a mercury column of density 13,595.1 kg/m³ under standard gravity, is 133.322387415 Pa. The relative difference of 1.4 × 10⁻⁷ has no measurable effect, blood pressure included. The conventional mmHg value is applied to both units: 1 atm gives 759.999892 mmHg, displayed as 760 to six significant digits.
Validity domainA tyre, compressor or diving-cylinder gauge almost always shows gauge pressure, measured above atmospheric pressure.
A tyre, compressor or diving-cylinder gauge almost always shows gauge pressure, measured above atmospheric pressure. At sea level it is about 1.013 bar below the absolute pressure. Physical tables and the ideal gas law use absolute pressure. The conversion factor is the same under both conventions; comparing a gauge value with an absolute one introduces an error of one atmosphere.