Pressure Units
| | mbar | bar | torr | Pa (Nm-2) | atm | lbf in-2 | kgf cm-2 | in Hg | mm Hg | in H20 | mm H2O |
| 1 mbar = | 1 | 1x10-3 | 0.75 | 102 | 9.869 x 10-4 | 1.45 x 10-2 | 1.02 x 10-3 | 2.953 x 10-2 | 0.75 | 0.402 | 10.2 |
| 1 bar = | 103 | 1 | 7.5 x 102 | 1 x 105 | 0.987 | 14.5 | 1.02 | 29.53 | 7.5 x 102 | 4.015 x 102 | 1.02 x 104 |
| 1 torr = | 1.333 | 1.333 x 10-3 | 1 | 1.333 x 102 | 1.316 x 10-1 | 1.934 x 10-2 | 1.36 x 10-3 | 3.937 x10 -2 | 1 | 0.535 | 13.59 |
| 1 Pa (Nm-2)= | 0.01 | 1x10-5 | 7.5 x 10-3 | 1 | 9.87 x 10-6 | 1.45 x 10-4 | 1.02 x 10-5 | 2.953 x 10-4 | 7.5 x 10-3 | 4.015 x 10-3 | 0.102 |
| 1 atm = | 1.013 x 103 | 1.013 | 7.6 x 102 | 1.013 x 105 | 1 | 14.7 | 1.033 | 29.92 | 7.6 x 102 | 4.068 x 102 | 1.033x104 |
| 1 lbin-2= | 68.95 | 6.895 x 10-2 | 51.71 | 6.895 x 103 | 6.805 x 10-2 | 1 | 7.03 x 10-2 | 2.036 | 51.71 | 27.68 | 7.03 x 102 |
| 1 kgf cm-2= | 9.807 x 102 | 0.981 | 7.356 x 102 | 9.807 x 104 | 0.968 | 14.22 | 1 | 28.96 | 7.356 x 102 | 3.937 x 102 | 104 |
| 1 in Hg = | 33.86 | 3.386 x 10-2 | 25.4 | 3.386 x 103 | 3.342 x 10-2 | 0.491 | 3.453 x 10-2 | 1 | 25.4 | 13.6 | 3.45 x 102 |
| 1 mm Hg = | 1.333 | 1.333 x 10-3 | 1 | 1.333 x 102 | 1.316 x 10-3 | 1.934 x 10-2 | 1.36 x 10-3 | 3.937 x 10-2 | 1 | 0.535 | 13.59 |
| 1 in H2O = | 2.491 | 2.491 x 10-3 | 1.868 | 2.491 x 102 | 2.458 x 10-3 | 3.613 x 10-2 | 2.54 x 10-3 | 7.356 x 10-2 | 1.868 | 1 | 25.4 |
| 1 mm H2O= | 9.807 x 10-2 | 9.807 x 10-5 | 7.354 x 10-2 | 9.807 | 9.677 x 10-5 | 1.42 x 10-3 | 1x10-4 | 2.896 x 10-3 | 7.354 x 10-2 | 3.394 x 10-2 | 1 |
Note also: 1 dyn cm-2 (barye) = 0.1 Pa (Nm-2) = 10-3 mbar.
Leak Rate Units
| | mbar l s-1 | torr l s-1 | atm cm3s-1 | lusec | atm ft3 min-1 | grams per year |
| (Freon 12) | ||||||
| 1 mbar l s-1 = | 1 | 0.75 | 0.987 | 7.5 x 102 | 2.097 x 10-3 | 1.58 x 105 |
| 1 torr l s-1 = | 1.333 | 1 | 1.316 | 103 | 2.795 x 10-3 | 2.083 x 105 |
| 1 atm cm3s-1 = | 1.013 | 0.76 | 1 | 7.6 x 102 | 2.12 x 10-3 | 1.582 x 105 |
| 1 lusec = | 1.333 x 10-3 | 0.001 | 1.32 x 10-3 | 1 | 2.79 x 10-6 | 2.083 x 102 |
| 1 atm ft3min-1 = | 4.78 x 102 | 3.58 x 102 | 4.72 x 102 | 3.58 x 105 | 1 | 7.45 x 107 |
| 1 gram per year | 6.4 x 10-6 | 4.8 x 10-6 | 6.32 x 10-6 | 4.8 x 10-3 | 1.34 x 10-8 | 1 |
| (Freon 12) |
