Measurement Units of Vacuum Data

The units pascal [Pa], kilopascal [kPa], bar [bar] and millibar [mbar] are most widely used in vacuum technology as units for pressure. The units are converted as follows:

0.001 bar = 0.1 kPa = 1 mbar = 100 Pa

On this website, all absolute pressure values are given in bar or mbar, all relative values in %. The % value is typical for a relative indication of the efficiency of a vacuum generator. Other units are used internationally. Some of them are included in the following table.

Vacuum/pressure conversion table

barN/cm2kPaatm, kp/cm2  mm H2OTorr; mm Hg  in Hg
bar1.00000 10.00000  100.0000  1.0197010,197.00 750.060029.5400
atm, kp/cm2  0.98070 9.80700  98.07001.0000010,332.00  735.560028.9700
mm H2O0.000100.001000.01000.000001.000.07400.0030
Torr; mm Hg0.001330.013330.13330.0013613.601.00000.0394
in Hg0.033800.338503.88500.03446345.4025.25001.0000


At the end of this chapter you will find additional conversion and unit tables.