Convert Torr to Bar (Torr → bar)

Converting torr to bars is straightforward: multiply by the conversion factor. Follow these three steps to do it by hand or in your head.

1. 1
   Take your value in torr

   Start with the number of torr (Torr) you want to convert.
2. 2
   Multiply by 0.001333

   The conversion factor from Torr to bar is 0.001333. Multiply your value by this number.
3. 3
   Read the result in bars

   The result is your value in bars (bar).

Multiply the value in torr by 0.001333. For the reverse direction, multiply by 750.06168.

• ✓1 Torr ≈ 1 mmHg (differ by ~1 ppm — negligible in practice).
• ✓1 atm = 760 Torr exactly.
• ✓Named after Evangelista Torricelli, inventor of the barometer.

• ✗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.

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

What is the Bar?

The bar equals exactly 100,000 pascals (100 kPa) and is the everyday pressure unit in European tire pressures, hydraulic systems, and meteorology. The unit was chosen to be approximately equal to atmospheric pressure at sea level (1 bar = 0.987 atm). European cars have tire pressures of about 2.0–2.5 bar (29–36 psi), industrial hydraulic systems operate at 100–700 bar, and wine bottles are pressurized to about 6 bar internally for sparkling wines. Although technically not an SI unit, the bar is widely accepted for use with the SI system. Weather forecasts in some countries use 'millibar' (1 mbar = 1 hPa = 100 Pa) for atmospheric pressure. The bar relates to the pascal (100,000 Pa = 1 bar), the kilopascal (100 kPa = 1 bar), the psi (1 bar ≈ 14.504 psi), the atmosphere (1 atm ≈ 1.013 bar), and the mbar (1,000 mbar = 1 bar). It strikes a practical balance between scientific precision and everyday usefulness.

• European tyre pressure gauges
• Scuba-diving depth pressure
• Hydraulic and pneumatic systems