Torr to mbar Converter
The torr is a pressure unit defined as exactly 1/760 of standard atmosphere (101,325 Pa), giving 1 torr = 133.322 Pa = 1.33322 mbar. The unit is named after Evangelista Torricelli,...
Formula
Source: Engineering Toolbox, NIST | Last reviewed: June 8, 2026
Examples
760 Torr
= 1013.2 mbar
Standard atmospheric pressure
1 Torr
= 1.333 mbar
1 Torr = 1.333 mbar
0.001 Torr
= 0.00133 mbar
High vacuum range (1 millitorr)
Quick Reference Table
| Torr | mbar |
|---|---|
| 0.001 | 0.00133 |
| 0.01 | 0.0133 |
| 0.1 | 0.133 |
| 1 | 1.333 |
| 10 | 13.33 |
| 100 | 133.3 |
| 760 | 1013.25 |
Where is this used?
Laboratory equipment: mass spectrometers, vacuum furnaces, and thin-film deposition systems frequently use both units.
Meteorological pressure readings cross-referenced with industrial vacuum specifications.
In the semiconductor equipment industry, the etch, deposition, and ion implant tools from Applied Materials, Lam Research, TEL, and Hitachi specify chamber pressure in mTorr or torr (US convention) for the process recipes, while the supporting vacuum pumps from Pfeiffer Vacuum (Germany), Edwards (UK/Japan), and Leybold (Germany) are rated in mbar or hPa — the conversion is required when integrating US-spec process tools with European or Asian vacuum pumps, and is also needed for the process recipe documentation in international fabs.
Pharmaceutical freeze drying (lyophilization) cycle development specifies the chamber pressure in mbar (the European convention in most equipment from GEA, IMA, Telstar) and the same value in mTorr on US-spec gauges (Varian, MKS), with the conversion at the cycle recipe boundary.
The conversion is exact and mechanical: 0.1 mbar = 75 mTorr, 0.05 mbar = 37.5 mTorr, 0.01 mbar = 7.5 mTorr, etc.
Mass spectrometry in analytical chemistry and pharmaceutical development uses torr for ion gauge readings (a typical UHV mass spectrometer operates at 10⁻⁹ to 10⁻¹¹ torr) while the same instrument's data system in European labs may display mbar or Pa, with the conversion applied in the data reduction.
Vacuum metallurgy (vacuum arc remelting for titanium and specialty alloys, vacuum induction melting for aerospace superalloys) specifies the chamber pressure in torr (US convention) or mbar (European convention) with the conversion at the melt recipe and the test certificate.
Meteorological pressure readings for weather forecasting, climate research, and air quality modeling are universally in hPa (= mbar) per the World Meteorological Organization standard, but older barometric measurements and some industrial process barometers (in petrochemical and natural gas operations) use inches of mercury (inHg) — the conversion chain inHg → torr → mbar is required when integrating historical climate data with modern meteorological databases.
Space simulation testing of spacecraft hardware per NASA-STD-7001 and ECSS-Q-ST-60 specifies the thermal vacuum chamber pressure in torr or Pa, with the conversion to mbar for the European test facility control systems.
Frequently Asked Questions
What vacuum ranges use torr vs mbar?
Rough vacuum (760–1 Torr, 1013–1.33 mbar), medium vacuum (1–10⁻³ Torr, 1.33–1.33×10⁻³ mbar), and high vacuum (below 10⁻³ Torr) are the typical ranges. US equipment tends to use Torr; European equipment uses mbar.
Why are both units still in use?
Historical reasons and regional preferences. The torr is deeply embedded in vacuum physics literature and US industry. The mbar is the SI-compatible unit preferred in Europe. Both will likely coexist indefinitely.
How does mbar relate to hPa?
1 mbar = 1 hPa exactly. Meteorologists prefer hPa because it aligns with SI naming conventions. In vacuum technology, mbar is the traditional term. The numerical value is identical.
Reviewed for accuracy
· Last reviewed: June 8, 2026
All calculations are for reference only. Always verify with manufacturer data and a qualified engineer for critical applications. Learn about our editorial process.