Vacuum Pressure – Units Converter

The table below can be used to convert between commonly used vacuum units:

%
Vacuum
Torr
(mm Mercury)
Micronpsia,
(lb/in2
abs)
Inches
Mercury
Absolute
Inches
Mercury
Gauge
kPa
abs
0.0760.0760,00014.729.920.00101.4
1.3750.0750,00014.529.50.4299.9
1.9735.6735,60014.228.91.0297.7
7.9700.0700,00013.527.62.3293.5
21.0600.0600,00011.623.66.3279.9
34.0500.0500,0009.719.710.2266.7
47.0400.0400,0007.715.714.2253.2
50.0380.0380,0007.315.014.9250.8
61.0300.0300,0005.811.818.1240
74.0200.0200,0003.97.8522.0726.6
87.0100.0100,0001.933.9425.9813.3
88.090.090,0001.743.5426.3812
89.580.080,0001.553.1526.7710.7
90.870.070,0001.352.7627.169.3
92.160.060,0001.162.3627.568
93.051.751,7001.002.0327.896.9
93.550.050,0000.971.9727.956.7
94.840.040,0000.771.5728.355.3
96.130.030,0000.581.1828.744
96.625.425,4000.491.0028.923.4
97.420.020,0000.390.78529.142.7
98.710.010,0000.1930.39429.531.3
99.07.67,6000.1470.29929.621.0
99.871.01,0000.019340.0393729.880.13
99.900.757500.01450.029529.890.1
99.990.101000.001930.0039429.9160.013
99.9990.01100.0001930.00039429.91960.0013
1000.0000029.920
  • 1 psi (lb/in2) = 6,894.8 Pa (N/m2) = 6.895×10-3 N/mm2 = 6.895×10-2 bar

vacuum units

 

Convert from % Vacuum to Unit of Pressure

The % of vacuum is a relative value where pressure at normal or standard atmosphere is the base value.

pv% = 100% – (pv / patm) 100%                                       (1)

where

pv% = vacuum (%)

pv = absolute pressure (psia, kPa, bar ..)

patm = absolute presure at normal or standard conditions (psia, kPa, bar ..)

Example – Pressure in kPa and % Vacuum

The vacuum with absolute pressure 4 kPa and standard pressure 101.4 kPa can be calculated as

pv% = 100% – ((4 kPa) / (101.4 kPa)) 100% 

       = 96.1 %

Example – Pressure in kPa and % Vacuum

The vacuum with absolute pressure 0.1 bar and standard pressure 1 bar can be calculated as

pv% = 100% – ((0.1 bar) / (1 bar)) 100% 

       = 90 %

Vacuum Ranges

Pressure
(Pa)
Low vacuum1×105 to 3×103
Medium vacuum3×103 to 1×10-1
High vacuum1×10-1 to 1×10-7
Ultra high vacuum1×10-7 to 1×10-10
Extremely high vacuum1×10-10
Perfect vacuum0
  • Outer space 1×10-4 to < 3×10-15