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Rebuilding civilization

Unit converters

Pressure

Pascals, bar, atmospheres, psi, kgf/cm², millimetres of mercury and metres of water column.

Equivalents

pascalPa
kilopascalkPa
megapascalMPa
millibar (hectopascal)mbar
barbar
atmosphereatm
kilogram-force per cm²kgf/cm²
pound per square inchpsi
millimetre of mercurymmHg
inch of mercuryinHg
metre of water columnm c.a.

How it is calculated

The value is converted to pascals (1 Pa = 1 N/m²) and from there to every unit. 1 bar = 100,000 Pa, 1 atm = 101,325 Pa = 760 mmHg = 1.01325 bar, 1 psi = 6895 Pa and 1 kgf/cm² = 0.980665 bar.

Water column: every 10 m of water height gives about 0.98 bar (1 kgf/cm²). A tank 25 m above a tap gives about 2.45 bar there when no water is flowing.

Keep in mind

  • Pressure gauges usually read gauge pressure (above atmospheric): a tyre at “2 bar” is at about 3 bar absolute.
  • Atmospheric pressure falls with altitude, roughly 12 % for every 1000 m in the lower layers.

See also