Gauge PSI, Absolute pressure PSI, Vacuum Inches Mercury, Vacuum millibar, vacuum kPa, Absolute pressure Torr, Gauge Vacuum mm mercury and percentage vacuum cross reference guide.

Altitude feet, Altitude meters, absolute pressure and gauge pressure inches mercury vacuum conversion table

Vacuum pressure unit conversion chart (absolute)

Convert percentage vacuum, atmospheres, PSIA, Torr (millimeters mercury mm Hg), Inches mercury In Hg, kPa (SI Unit), bar and mbar.

Vacuum pressure unit conversions chart (relative)

Percentage vacuum, atmosphere ATM, PSIG negative gauge pressure, Inches Mercuury negative gauge, kPa negative gauge, bar negative gauge and millimbar mbat negative gauge conversions.

Pascal (Pa)
Pa=N/m² : The Pascal (Pa) is the SI unit, 1 Bar = 10E5.Pa = 101 kPa = 0.1 MPa
A pressure of 1 Pa applied on a surface A=1m² generates a force F=1N (1N=1 kg.m.s-²).

1 Torr = 4/3 mbar, =133.3 Pa

1 standard atmosphere, 1 atm. = 760 Torr = 1013 mbar
1 tech. atmosphere, 1 At = 1kp/cm² = 981 mbar

That relative Vacuum in %: V% = (Po-P)/Po, 300mbar => (1013-300)/1013= 70% Vacuum
or P=Po-(Po.V%), 30% in Torr => 760-(760.0.3)=532 Torr


atmospheric pressure (1 Atm.)
1.013 bar = 1013 millibars (mbar)
= 101325 Pascal (Pa), = 101 kPa
= 760 Millimetre mercury column (mmHgA) = 760 Torr (1 Torr = 1 mm HgA)
= 29.92 inches of mercury absolute (in HgA),
= 14.7 pounds per square inch absolute (lb/in², PSIA)

Atmospheric pressure is often measured with a mercury barometer, and a height of approximately 760 millimetres (30 in) of mercury is often used to illustrate (and measure) atmospheric pressure. However, since mercury is not a substance that humans commonly come in contact with, water often provides a more intuitive way to visualize the pressure of one atmosphere:

One atmosphere (101 kPa or 14.7 psi) is the amount of pressure that can lift water approximately 10.3 m (34 ft).

10.3 m (34 ft) is also the maximum height to which a column of water can be drawn up by suction / via a vacuum.