# Pressure

The coherent SI unit for Pressure is the Newton per square metre, Nm-2, or Pascal, Pa.

Factors in boldface are exact.

The convention of adding a standard atmosphere (101325 Pa) is used when changing reference conditions from absolute to gauge. Gauge pressure is signified by the suffix g.

Convert From To Multiply Std
kilo pascal kPa Pa 1000 1
mega pascal MPa Pa 106 1
giga pascal GPa Pa 109 1
kilogram-force per square metre kgf/m2 Pa 9.80665 4
kilogram-force per square centimetre kgf/cm2 Pa 98066.5 2
pound-force per square foot lbf/ft2 Pa 47.88025898 3
pound-force per square inch lbf/in2 Pa 6894.757293168361 1
pound-force per square inch psi Pa 6894.757293168361 1
bar bar Pa 105 3
millibar mbar Pa 100 3
millimetre of mercury, conventional mmHg Pa 133.3224 4
millimetre of water, conventional mmH2O (con) Pa 9.80665 1
millimetre of water @ 60°F mmH2O @ 60°F Pa 248.84/25.4 1
inch of mercury, conventional inHg (con) Pa 3386.389 4
inch of mercury @ 32°F inHg @ 32°F Pa 3386.38 1
inch of mercury @ 60°F inHg @ 60°F Pa 3376.85 1
inch of water, conventional inH2O (con) Pa 249.08891 4
inch of water @ 39.2°F inH2O @ 39.2°F Pa 249.082 1
inch of water @ 60°F inH2O @ 60°F Pa 248.84 1
foot of water, conventional ftH2O (con) Pa 2989.06692 4
foot of water @ 39.2°F ftH2O @ 39.2°F Pa 2988.98 1
torr Torr Pa 101325/760 1
atmosphere, standard atm Pa 101325 3

1: BS 350:2004 Section 33

2: BS 350:2004 Table 32

3: BS 350:2004 Table 33

4: BS 350:2004 Table 34

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