Conversion of units
Name of unit Symbol Definition Relation to SI units
atmosphere ( standard ) atm ≡ 101 325 Pa
atmosphere ( technical ) at ≡ 1 kgf/cm = 9.806 65 × 10 Pa
bar bar ≡ 100 000 Pa ≡ 10 Pa
barye ( cgs unit ) ≡ 1 dyn/cm = 0.1 Pa
centimetre of mercury cmHg ≡ 13 595 .1 kg/m × 1 cm × ɡ 0 ≈ 1.333 22 × 10 Pa
centimetre of water ( 4 °C ) cmH 2 O ≈ 999.972 kg/m × 1 cm × ɡ 0 ≈ 98.0638 Pa
foot of mercury ( conventional ) ftHg ≡ 13 595 .1 kg/m × 1 ft × ɡ 0 ≈ 4.063 666 × 10 Pa
foot of water ( 39.2 °F ) ftH 2 O ≈ 999.972 kg/m × 1 ft × ɡ 0 ≈ 2.988 98 × 10 Pa
inch of mercury ( conventional ) inHg ≡ 13 595 .1 kg/m × 1 in × ɡ 0 ≈ 3.386 389 × 10 Pa
inch of water ( 39.2 °F ) inH 2 O ≈ 999.972 kg/m × 1 in × ɡ 0 ≈ 249.082 Pa
kilogram-force per square millimetre kgf/mm ≡ 1 kgf/mm = 9.806 65 × 10 Pa
kip per square inch ksi ≡ 1 kipf/sq in ≈ 6.894 757 × 10 Pa
long ton per square foot ≡ 1 long ton × ɡ 0 / 1 sq ft ≈ 1.072 517 801 1595 × 10 Pa
micrometre of mercury μmHg ≡ 13 595 .1 kg/m × 1 μm × ɡ 0 ≈ 0.001 torr ≈ 0.133 3224 Pa
millimetre of mercury mmHg ≡ 13 595 .1 kg/m × 1 mm × ɡ 0 ≈ 1 torr ≈ 133.3224 Pa
millimetre of water ( 3.98 °C ) mmH 2 O ≈ 999.972 kg/m × 1 mm × ɡ 0 = 0.999 972 kgf/m = 9.806 38 Pa
pascal ( SI unit ) Pa ≡ N/m = kg/ ( m·s ) = 1 Pa
pièze ( mts unit ) pz ≡ 1000 kg/m·s = 10 Pa = 1 kPa
pound per square foot psf ≡ 1 lbf/ft ≈ 47.880 26 Pa
pound per square inch psi ≡ 1 lbf/in ≈ 6.894 757 × 10 Pa
Tables of conversion factors -- Pressure or mechanical stress
Conversion of units is the conversion between different units of measurement for the same quantity, typically through multiplicative conversion factors.