Convert millimeter of mercury to atmosphere
1 mmHg = 0.001315789661 atm
sig figs
1 mmHg = 0.00132 atm
1 mmHg in every pressure unit
| microbar | 1,330 μbar |
| barye | 1,330 Ba |
| millitorr | 1,000 mTorr |
| pascal | 133 Pa |
| millimeter of water column | 13.6 mmH₂O |
| pound per square foot | 2.78 lb/ft² |
| centimeter of water column | 1.36 cmH₂O |
| hectopascal | 1.33 hPa |
| millibar | 1.33 mbar |
| torr | 1 Torr |
| millimeter of mercury | 1 mmHg |
| inch of water column | 0.535 in w.g. |
| kilopascal | 0.133 kPa |
| foot of water column | 0.0446 ft H₂O |
| inch of mercury | 0.0394 inHg |
| pound per square inch | 0.0193 psi |
| meter of water column | 0.0136 m H₂O |
| decibar | 0.0133 dbar |
| kilogram-force per square centimeter | 0.00136 kgf/cm² |
| bar | 0.00133 bar |
| atmosphere | 0.00132 atm |
| megapascal | 0.000133 MPa |
| kip per square inch | 0.0000193 ksi |
| gigapascal | 1.33e-07 GPa |
| million pounds per square inch | 1.93e-08 Mpsi |
Worth knowing
millimeter of mercury: The torr and the millimetre of mercury are not identical. The torr is defined as exactly 1/760 of a standard atmosphere, or 133.3223684... Pa, while mmHg is 133.322387415 Pa. They differ by about one part in seven million, which is irrelevant for blood pressure and can matter in precision vacuum metrology. Full definition →
How the conversion works
Multiply by 0.001315789661 to go from millimeter of mercury to atmosphere, or divide by it to go back. Every conversion on this site routes through the SI value (Pa) rather than a table of pairwise factors, so a round-trip returns exactly what you started with.
Going the other way? atmosphere to millimeter of mercury: 1 atm = 759.9998917 mmHg.
millimeter of mercury to atmosphere: common values
| 1 mmHg | 0.0013157897 atm |
| 2 mmHg | 0.0026315793 atm |
| 3 mmHg | 0.003947369 atm |
| 5 mmHg | 0.0065789483 atm |
| 10 mmHg | 0.013157897 atm |
| 15 mmHg | 0.019736845 atm |
| 20 mmHg | 0.026315793 atm |
| 25 mmHg | 0.032894742 atm |
| 50 mmHg | 0.065789483 atm |
| 75 mmHg | 0.098684225 atm |
| 100 mmHg | 0.13157897 atm |
| 250 mmHg | 0.32894742 atm |
| 500 mmHg | 0.65789483 atm |
| 1000 mmHg | 1.3157897 atm |