Atmospheres (atm) to Millimeters of mercury (mmHg) Conversion
Atmospheres
The standard atmosphere (atm) is a unit of pressure defined as exactly 101,325 Pa, representing the approximate mean atmospheric pressure at sea level. It remains in use in chemistry for expressing gas pressures in thermodynamic tables and standard conditions (STP: 0 °C and 1 atm). One atmosphere supports a mercury column of exactly 760 mm — the basis of the mercury barometer invented by Torricelli in 1643. In deep-sea diving, pressure is expressed in atmospheres absolute (ATA).
Millimeters of mercury
The millimetre of mercury (mmHg) is a unit of pressure equal to the pressure exerted by a 1 mm column of mercury at 0 °C and standard gravity — approximately 133.322 Pa. It is the universal clinical standard for measuring blood pressure: normal adult blood pressure is approximately 120/80 mmHg (systolic/diastolic). The mmHg is also used in ophthalmology (intraocular pressure, normal ≈ 10–21 mmHg) and respiratory physiology.
| Atmospheres (atm) | Millimeters of mercury (mmHg) |
|---|---|
| 0.1 atm | 75.999999099926 mmHg |
| 1 atm | 759.99999099926 mmHg |
| 2 atm | 1519.9999819985 mmHg |
| 3 atm | 2279.9999729978 mmHg |
| 5 atm | 3799.9999549963 mmHg |
| 10 atm | 7599.9999099926 mmHg |
| 20 atm | 15199.999819985 mmHg |
| 30 atm | 22799.999729978 mmHg |
| 50 atm | 37999.999549963 mmHg |
| 100 atm | 75999.999099926 mmHg |
| 1000 atm | 759999.99099926 mmHg |
Frequently Asked Questions (FAQ)
How many millimeters of mercury are in 1 atmospheres?
1 atmospheres (atm) is exactly 760.000 millimeters of mercury (mmHg).
How do I convert atmospheres to millimeters of mercury?
Multiply the value in atmospheres by 760.000 to get the result in millimeters of mercury. Or use the converter above — type any number and see the result instantly.