Millibar To Torr Converter

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ConvertReference Technical Standards Team

All values and formulas are validated through our editorial review process and cross-checked against internationally recognized reference standards (NIST, BIPM, CODATA).

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Last reviewed: December 08, 2025

Conversion Factors

1 millibar = 0.75006168270417 torr
1 torr = 1.33322368421053 millibar

(Exact factors: 0.75006168270417 and 1.33322368421053)

Sources: NIST · BIPM

About This Millibar And Torr Converter

This tool helps you compare two pressure units: millibar and torr. It gives you a fast, clear display of the corresponding value. You can click the swap button to switch between units. Designed for quick, accurate results in everyday measurements.

What Are Millibars And Torrs?

What Is A Millibar?

Millibar (mbar) is a unit of pressure equal to one-thousandth of a bar. Since 1 bar = 100,000 pascals, 1 mbar = 100 pascals (0.1 kPa). It is a non-SI unit commonly used with SI in meteorology and engineering; symbol: mbar (mb). It equals 1 hPa (1 mbar = 1 hPa). Example: sea-level pressure is about 1013 mbar (~101.3 kPa).

What Is A Torr?

Torr is a unit of pressure equal to 1 millimeter of mercury (mmHg) at 0°C. It is defined as 1 mmHg and equals about 133.322 Pa; 1 atm = 760 torr. It is a non-SI unit accepted for use with the SI. Symbol: torr. Real-world example: standard sea-level air pressure is about 760 torr (≈101.3 kPa).

When To Use Millibar Vs Torr

Millibar Usage

Millibar is a unit of atmospheric pressure used in meteorology and weather reports. It is used in several countries, including the United Kingdom, France, Germany, and Italy.

Torr Usage

Torr is still used as a pressure unit in some medical and scientific contexts in the United States, the United Kingdom, Germany, and Japan.

How To Convert Between Millibars And Torrs

Conversion Formulas

Millibar to Torr:
millibar × 0.75006168270417 = torr

Torr to Millibar:
torr × 1.33322368421053 = millibar

Step-by-Step Guide

Millibar to Torr

Take your value in millibars.
Multiply by 0.75006168270417.
The result is in torrs.

Torr to Millibar

Take your value in torrs.
Multiply by 1.33322368421053.
The result is in millibars.

Example: Convert 0.05 millibars to torrs.

Exact: 0.05 × 0.75006168270417 = 0.0375030841352085 torrs.
Rounded: approximately 0.0375031 torrs.

Example: Convert 5 torrs to millibars.

Exact: 5 × 1.33322368421053 = 6.66611842105263 millibars.
Rounded: approximately 6.66612 millibars.

History & Context

Historically, scientists studied air pressure with barometers, and units carried the names millibar and torr. The torr is named after Evangelista Torricelli, who built an early, reliable barometer and showed that air has weight. This gave birth to a unit used in vacuum science and high-pressure experiments. The millibar grew from the adoption of the metric system to measure atmospheric pressure in weather work, flight, and research, becoming common in many meteorology reports. Both units reflect a time when pressure was written in practical, nearby terms rather than precise numbers, and over time the use of these units has shifted toward other metric measures, while the torr survives in labs and some specialized weather contexts.

Practical Use

In a thin-film coating experiment, the vacuum chamber’s gauge might read pressure in millibars, while the process controller expects Torr, so you convert millibar to Torr to set the right conditions. Converting the value ensures the film grows under the intended low-pressure environment and the equipment performance matches the spec. In a laboratory vacuum system, when a technician notes a pressure of a few Torr on one instrument but a different system reports millibars, you convert Torr to millibar to compare readings and verify leak checks. Accurate cross‑checking helps prevent mismatches that could affect experiments or the chamber’s warranty.

Common Mistakes When Converting Between Millibars And Torrs

Treat millibar and torr as the same unit.
Assume there is no conversion factor between millibar and torr.
Confuse torr with mmHg as if they were different units.
Round intermediate results too early during the conversion.

Mental Shortcuts For Quick Conversions

Memorization: 1 mbar ≈ 0.75 torr. Inverse: 1 torr ≈ 1.33 mbar. Estimation only—use a precise converter for accuracy.

Millibars And Torrs Conversion Graph

Conversion Table For Millibar And Torr

Common conversion values
Millibars	Torrs
0.01	0.00750062
0.05	0.0375031
0.1	0.0750062
0.2	0.150012
0.5	0.375031
1	0.750062
2	1.50012
5	3.75031
10	7.50062
20	15.0012

Values are rounded for display; internal calculations use the exact conversion factors between millibar and torr (0.75006168270417 and 1.33322368421053).

Dataset & API Access

Programmatic Access

Free JSON API with stable endpoints and predictable keys for automated bidirectional conversions.

Endpoint: https://convertreference.org/api/v1/convert/millibar-to-torr.json

Content Type: application/json

Documentation: View API docs

Licensing

License: CC0 1.0 Universal (Public Domain)

See all datasets

Data & Editorial Process

All numerical values and formulas are generated from the Pint scientific unit library (v0.25), using constants consistent with the BIPM SI Brochure (9th Edition) and NIST Special Publication 811. Explanatory text is drafted with AI assistance and reviewed by ConvertReference editors for clarity and accuracy. This converter is completely free to use, and all calculations are performed locally in your browser and never sent to a server.

2025-12-08 – Generated: Page created using Pint v0.25 verified constants.
2025-12-08 – Reviewed: Verified by ConvertReference editors; no numerical changes required.

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