Torr (Torr) to Atmospheres (atm) Conversion
Torr
The torr is a unit of pressure named after Evangelista Torricelli, the Italian physicist who invented the mercury barometer in 1643. One torr is defined as exactly 1/760 of a standard atmosphere (approximately 133.322 Pa). Numerically nearly identical to the millimetre of mercury (mmHg), it differs by less than 0.000015%. The torr is used in vacuum science and engineering: rough vacuum is 1–100 torr, fine vacuum 10⁻³–1 torr, and ultra-high vacuum below 10⁻⁹ torr.
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).
| Torr (Torr) | Atmospheres (atm) |
|---|---|
| 0.1 Torr | 0.00013157894736738 atm |
| 1 Torr | 0.0013157894736738 atm |
| 2 Torr | 0.0026315789473476 atm |
| 3 Torr | 0.0039473684210215 atm |
| 5 Torr | 0.0065789473683691 atm |
| 10 Torr | 0.013157894736738 atm |
| 20 Torr | 0.026315789473476 atm |
| 30 Torr | 0.039473684210215 atm |
| 50 Torr | 0.065789473683691 atm |
| 100 Torr | 0.13157894736738 atm |
| 1000 Torr | 1.3157894736738 atm |
Frequently Asked Questions (FAQ)
How many atmospheres are in 1 torr?
1 torr (Torr) is exactly 0.001316 atmospheres (atm).
How do I convert torr to atmospheres?
Multiply the value in torr by 0.001316 to get the result in atmospheres. Or use the converter above — type any number and see the result instantly.