Convert Millimeters of Mercury to Torr
Convert Millimeters of Mercury (mmHg) to Torr (Torr) instantly and accurately.
Conversion Formula
Torr = mmHg × 1.000000142
About Millimeters of Mercury
One millimetre of mercury (mmHg) = pressure from 1 mm of mercury at 0°C and standard gravity = 133.322 Pa. Clinical medicine worldwide uses mmHg for blood pressure (normal ~120/80 mmHg) and for gas partial pressures in physiology: arterial O₂ ~95-100 mmHg; CO₂ ~40 mmHg; alveolar O₂ ~104 mmHg. Ophthalmologists measure intraocular pressure in mmHg (normal 10-21; glaucoma risk above 21). Vacuum equipment ratings are also given in mmHg. 760 mmHg = 1 atm. 1 mmHg = 133.322 Pa.
About Torr
The torr is defined as exactly 1/760 of a standard atmosphere ≈ 133.322 Pa - effectively replacing mmHg with an exact definition. Named after Evangelista Torricelli (1608-1647), inventor of the barometer. Vacuum science universally uses torr: rough vacuum 760-1 torr; medium vacuum 1-10⁻³ torr; high vacuum 10⁻³-10⁻⁷ torr; ultra-high vacuum below 10⁻⁹ torr. UHV systems for surface science, particle accelerator beam tubes, and space simulation chambers reach 10⁻¹¹-10⁻¹² torr. 1 torr = 133.322 Pa.
Quick Reference Table
| Millimeters of Mercury (mmHg) | Torr (Torr) |
|---|---|
| 1 mmHg | 1 Torr |
| 2 mmHg | 2 Torr |
| 5 mmHg | 5 Torr |
| 10 mmHg | 10 Torr |
| 25 mmHg | 25 Torr |
| 50 mmHg | 50 Torr |
| 100 mmHg | 100 Torr |