How to convert millimeters of mercury to atmospheres
Formula: atm = mmHg ÷ 760
Worked example: 120 mmHg → 120 ÷ 760 = 0.157895 atm
Millimeters of mercury to atmospheres conversion chart
| Millimeters of mercury (mmHg) | Atmospheres (atm) |
|---|---|
| 60 mmHg | 0.0789474 atm |
| 70 mmHg | 0.0921053 atm |
| 80 mmHg | 0.105263 atm |
| 90 mmHg | 0.118421 atm |
| 100 mmHg | 0.131579 atm |
| 110 mmHg | 0.144737 atm |
| 120 mmHg | 0.157895 atm |
| 130 mmHg | 0.171053 atm |
| 140 mmHg | 0.184211 atm |
| 160 mmHg | 0.210526 atm |
| 180 mmHg | 0.236842 atm |
| 200 mmHg | 0.263158 atm |
| 760 mmHg | 1 atm |
What is a millimeter of mercury?
The millimeter of mercury, about 133.32 pascals, comes from mercury barometers. It remains the unit of blood pressure worldwide: a reading of 120/80 mmHg means a systolic pressure of 120 and a diastolic pressure of 80.
What is an atmosphere?
The standard atmosphere is defined as exactly 101,325 pascals, the average air pressure at sea level. Divers count roughly one extra atmosphere for every 10 meters, or 33 feet, of seawater.