Convert Torr to Pound per Square Inch (Torr → psi)
The torr equals one millimeter of mercury and is used in vacuum-system specifications and laboratory instruments.
Torr to Pound per Square Inch Conversion Table
10 common values| Torr | Pound per Square Inch |
|---|---|
| 1 Torr | 0.019337 psi |
| 5 Torr | 0.096684 psi |
| 10 Torr | 0.193368 psi |
| 25 Torr | 0.483419 psi |
| 50 Torr | 0.966839 psi |
| 100 Torr | 1.933678 psi |
| 200 Torr | 3.867355 psi |
| 500 Torr | 9.668387 psi |
| 1,000 Torr | 19.336775 psi |
| 5,000 Torr | 96.683874 psi |
How to Convert Torr to Pound per Square Inch Manually
Step by StepConverting torr to psi is straightforward: multiply by the conversion factor. Follow these three steps to do it by hand or in your head.
- 1Take your value in torrStart with the number of torr (Torr) you want to convert.
- 2Multiply by 0.019337The conversion factor from Torr to psi is 0.019337. Multiply your value by this number.
- 3Read the result in psiThe result is your value in psi (psi).
Formula
Multiply the value in torr by 0.019337. For the reverse direction, multiply by 51.714933.
psi = Torr × 0.019337Torr = psi × 51.714933Tips
Use these in everyday conversions- 1 Torr ≈ 1 mmHg (differ by ~1 ppm — negligible in practice).
- 1 atm = 760 Torr exactly.
- Named after Evangelista Torricelli, inventor of the barometer.
Common Mistakes
Avoid these- Assuming torr and mmHg are truly identical — they differ by ~10⁻⁷; only matters in metrology.
- Using Torr in everyday context — obscure outside vacuum engineering.
- Mixing Torr and mTorr without specification.
About Torr and Pound per Square Inch
What is the Torr?
The torr equals approximately 1.0000003 mmHg (essentially identical, 133.322 Pa) and is named after Italian physicist Evangelista Torricelli (1608–1647), who invented the mercury barometer. The torr is widely used in vacuum-system specifications, laboratory instruments, and high-vacuum physics. Vacuum levels are categorized: 'low vacuum' is 760 to 1 torr, 'medium vacuum' 1 to 10⁻³ torr, 'high vacuum' below 10⁻³ torr. Mass spectrometers, electron microscopes, and semiconductor manufacturing systems require high vacuum (10⁻⁶ to 10⁻⁹ torr). The torr relates to the mmHg (essentially equal), the pascal (1 torr ≈ 133.3 Pa), the millibar (1 torr ≈ 1.333 mbar), and the atmosphere (760 torr = 1 atm). Modern scientific publications increasingly use the pascal, but the torr remains entrenched in vacuum technology.
- Vacuum-chamber pressure readings
- Semiconductor manufacturing
- Older physics literature
Low-vacuum: 760 to 25 torr. High-vacuum: 10⁻³ to 10⁻⁹ torr. Semiconductor fabrication: often below 10⁻⁶ torr.
What is the Pound per Square Inch?
Pounds per square inch (psi) equals approximately 6,895 pascals and is the standard pressure unit in American tire pressures, hydraulics, and gas-cylinder specifications. American car tires are typically inflated to 30–35 psi, household water systems run at 40–60 psi, and scuba tanks are filled to 3,000 psi (about 200 bar). The psi is essential in American engineering for stress calculations, hydraulic systems, and pneumatic equipment. Two variants exist: 'psig' (gauge, measured above atmospheric) and 'psia' (absolute, including atmosphere) — gauge is the default unless specified. The psi relates to the pascal (1 psi ≈ 6,895 Pa), the kilopascal (1 psi ≈ 6.895 kPa), the bar (14.504 psi = 1 bar), the atmosphere (14.696 psi = 1 atm), and the inch of mercury (1 inHg ≈ 0.491 psi). Outside the US, kPa or bar dominate.
- US tyre pressures
- US plumbing and water system specs
- US compressed-air tool ratings
US tyre: 32–35 psi. Water supply: 40–60 psi. SCUBA tank: 3000 psi. Car AC system: 30–200 psi.