Convert Pascals to Torr

The Pascal (symbol: Pa) is a unit of pressure. The SI derived unit of pressure (and stress), formally defined as one newton per square meter (N/m²) by ISO 80000-4. Named for 17th-century French mathematician Blaise Pascal, whose 1647-48 Puy-de-Dôme experiment established that atmospheric pressure decreases with altitude. The pascal is a small unit — standard sea-level atmospheric pressure is exactly 101,325 Pa per the BIPM SI Brochure — so working engineering and meteorology use multiples: kilopascals (kPa) for everyday gauge pressures, megapascals (MPa) for material strength, hectopascals (hPa) for barometric readings (1 kPa = 10 hPa). The pascal is the universal SI reference for pressure across scientific publication (Physical Review, J. Fluid Mechanics), thermodynamic state tables (NIST REFPROP), and international engineering codes (ASME, EN, JIS). Converting Pa to psi is a divide-by-6894.76; Pa to bar is divide-by-100,000.

It belongs to the metric measurement system.

Pascals are commonly used in tire inflation, weather reporting, scuba diving, and engineering.

The Torr (symbol: torr) is a unit of pressure. A unit of pressure defined as exactly 1/760 of a standard atmosphere (≈ 133.322 Pa). Named after 17th-century physicist Evangelista Torricelli, who in 1643 invented the mercury barometer while studying why suction-lift pumps fail above ~10 m — establishing that the atmosphere itself has weight. The torr is the primary unit in modern vacuum technology and semiconductor fabrication: a "rough vacuum" is ~1 torr, "medium vacuum" 10⁻³ torr (typical of mechanical-pump-only systems), "high vacuum" 10⁻⁶ torr (achievable with turbomolecular pumps, used in mass spectrometry and electron microscopy), and "ultrahigh vacuum" (UHV) 10⁻⁹ torr or lower (semiconductor MBE, surface science, particle accelerators). Manufacturing fabs quote chamber pressures in torr or mTorr (10⁻³ torr) at every process step. Numerically the torr is almost identical to the mmHg (1 torr ≈ 1.000000 mmHg under modern definitions; historically they differed by 0.000015%).

Torr are commonly used in tire inflation, weather reporting, scuba diving, and engineering.