Convert Torr to Pascal (Torr → Pa)

Converting torr to pascals 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 133.32237

   The conversion factor from Torr to Pa is 133.32237. Multiply your value by this number.
3. 3
   Read the result in pascals

   The result is your value in pascals (Pa).

Multiply the value in torr by 133.32237. For the reverse direction, multiply by 0.007501.

• ✓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 Pascal?

The pascal is the SI unit of pressure, equal to 1 newton per square meter (1 N/m²). Named after French mathematician and physicist Blaise Pascal (1623–1662), it became the SI standard in 1971. One pascal is a very small pressure: atmospheric pressure at sea level is about 101,325 Pa, the human breath exerts roughly 100 Pa above ambient, and tire pressure is in the hundreds of thousands of pascals. Because the pascal is small, the kilopascal (1 kPa = 1,000 Pa), megapascal (1 MPa = 10⁶ Pa), and gigapascal (1 GPa = 10⁹ Pa) are more commonly used in practice. Modern weather forecasts use hectopascals (1 hPa = 100 Pa = 1 millibar). The pascal relates to the bar (1 bar = 100,000 Pa), the psi (1 psi ≈ 6,895 Pa), the atmosphere (1 atm = 101,325 Pa), and mmHg (1 mmHg ≈ 133.3 Pa). Scientific and engineering publications use the pascal universally.

• Scientific and engineering calculations
• Ventilation and HVAC airflow pressures
• Acoustic pressure (sound) measurements