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Torr to Millibar Converter

Convert torr to millibars with our free online pressure converter.

Quick Answer

1 Torr = 1.333224 millibars

Formula: Torr × conversion factor = Millibar

Use the calculator below for instant, accurate conversions.

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All conversion formulas on UnitsConverter.io have been verified against NIST (National Institute of Standards and Technology) guidelines and international SI standards. Our calculations are accurate to 10 decimal places for standard conversions and use arbitrary precision arithmetic for astronomical units.

Last verified: February 2026Reviewed by: Sam Mathew, Software Engineer

Torr to Millibar Calculator

How to Use the Torr to Millibar Calculator:

  1. Enter the value you want to convert in the 'From' field (Torr).
  2. The converted value in Millibar will appear automatically in the 'To' field.
  3. Use the dropdown menus to select different units within the Pressure category.
  4. Click the swap button (⇌) to reverse the conversion direction.
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How to Convert Torr to Millibar: Step-by-Step Guide

Converting Torr to Millibar involves multiplying the value by a specific conversion factor, as shown in the formula below.

Formula:

mbar = Torr × 1.33322

Example Calculation:

1 Torr = 1.333224 mbar

Disclaimer: For Reference Only

These conversion results are provided for informational purposes only. While we strive for accuracy, we make no guarantees regarding the precision of these results, especially for conversions involving extremely large or small numbers which may be subject to the inherent limitations of standard computer floating-point arithmetic.

Not for professional use. Results should be verified before use in any critical application. View our Terms of Service for more information.

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What is a Torr and a Millibar?

The Torr (symbol: Torr) is a unit of pressure based on an absolute scale. It is not an SI unit, but it is widely used in science and engineering.

The Modern Definition: 1 Torr is defined as exactly 1/760 of a standard atmosphere (1 atm).

Since a standard atmosphere is defined as exactly 101,325 Pascals (Pa), the exact value of one Torr is: 1 Torr = 101,325 / 760 Pascals ≈ 133.322368421 Pascals.

** Torr vs. mmHg**: Historically, the Torr was intended to be same as the millimeter of mercury (mmHg). However, because the density of mercury changes with temperature and local gravity varies across the Earth, the mmHg is not a "true" absolute unit. To solve this, the Torr was redefined as a fixed fraction of an atmosphere, making it a perfectly stable unit regardless of where or the temperature at which you measure it.

Key standard relationships:

  • 1 Torr = 1,000 milliTorr (mTorr)
  • 760 Torr = 1 standard atmosphere (atm)
  • 1 Torr ≈ 1.333 millibars (mbar)
  • 1 Torr ≈ 0.0193 PSI (pounds per square inch)

1 mbar = 100 Pa = 1 hPa (exactly) = 0.001 bar = 0.0145 PSI = 0.75 mmHg = 0.000987 atm

Key relationship: 1 mbar = 1 hPa (exact equivalence)

Note: The Torr is part of the imperial/US customary system, primarily used in the US, UK, and Canada for everyday measurements. The Millibar belongs to the imperial/US customary system.

History of the Torr and Millibar

: From the First Barometer to Modern Vacuums

The history of the Torr is the history of our understanding of the "void" and the air around us.

1. Evangelista Torricelli and the "Sea of Air" (1643)

Before the 1640s, scientists believed that "nature abhors a vacuum" and that space was always filled with something. Evangelista Torricelli, a student of Galileo, challenged this. He filled a glass tube with mercury and inverted it into a bowl. Instead of all the mercury flowing out, it stopped at a height of about 76 cm (760 mm).

Torricelli correctly deduced that it wasn't a "pull" from the vacuum at the top of the tube, but the weight of the atmosphere pushing down on the mercury in the bowl that held the liquid up. He famously stated: "We live submerged at the bottom of an ocean of elementary air."

2. The Birth of the Name (1913)

For centuries, pressure was simply measured in "inches of mercury" or "millimeters of mercury." In 1913, the unit was formally named the Torr to honor Torricelli.

3. The Great Redefinition (1954)

As science became more precise, the variance in mercury density became a problem (a "millimeter of mercury" in the Arctic was technically different from one at the Equator). In 1954, at the 10th General Conference on Weights and Measures, the Standard Atmosphere was fixed at exactly 101,325 Pascals. Consequently, the Torr was redefined as exactly 1/760 of that value, decoupling it from the physical properties of mercury forever.

Common Uses and Applications: torr vs millibars

Explore the typical applications for both Torr (imperial/US) and Millibar (imperial/US) to understand their common contexts.

Common Uses for torr

When to Use millibars

Aviation: Altimeter settings (pilots say "1015 millibars"). Maritime: Marine weather forecasts, ship barometers. Meteorology: Historical weather data (pre-1980s). Diving: Depth pressure calculations (sometimes).

Additional Unit Information

About Torr (Torr)

What is the difference between Torr and mmHg?

For almost all practical, medical, and industrial purposes, they are the same. However, scientifically:

  • Torr is defined as exactly 1/760 of a Standard Atmosphere (Standardized in 1954).
  • mmHg (millimeter of mercury) is based on the actual weight of liquid mercury, which changes slightly depending on gravity and temperature.
  • The difference is 1 part in 7 million. Unless you are building a particle accelerator, you can treat them as identical.

Why is Torr used in vacuum technology?

Torr is the preferred unit because most vacuum systems are based on pumping down from atmospheric pressure. Since 760 Torr is a standard atmosphere, it's very easy for an engineer to know how "far" they have to go. It also uses a logarithmic scale naturally, making it easy to talk about 10⁻⁶ or 10⁻⁹ Torr levels.

Is a Torr a "Metric" unit?

No. The official SI unit for pressure is the Pascal (Pa). However, because 1 Pascal is such a small amount of pressure (about the weight of a dollar bill on a table), scientists in specific fields prefer the Torr for convenience.

How do you convert Torr to PSI?

Multiply your Torr value by 0.0193368. Formula: PSI = Torr × 0.0193368 Example: 100 Torr ≈ 1.93 PSI.

What is a "milliTorr" (mTorr)?

Also known as a Micron, a milliTorr is 1/1,000th of a Torr. It is commonly used in "roughing" vacuum pumps (like the one in your school's physics lab or a high-end food sealer).

Is 0 Torr possible?

A "perfect" vacuum (exactly 0 Torr) is theoretically impossible according to quantum mechanics. Even in deep intergalactic space, there is a pressure of about 10⁻¹⁷ Torr due to a few stray hydrogen atoms and cosmic radiation.

Is Torr used in the medical field?

Yes, but doctors almost always call it mmHg. When a nurse says your blood pressure is "120 over 80," they are literally saying "120 Torr systolic and 80 Torr diastolic."

Who is the unit Torr named after?

It is named after Evangelista Torricelli, the Italian physicist who proved that air has weight and invented the mercury barometer in 1643.

How many Pascals are in a Torr?

Exactly 133.322368... Pascals. For most calculations, using 133.3 is sufficient.

What happens if you are exposed to 0 Torr?

This is "space vacuum." Contrary to movies, your head doesn't explode. However, the oxygen in your blood would diffuse out of your lungs into the vacuum, causing you to lose consciousness in about 15 seconds. Your skin is tough enough to hold "you" together, but you would swell up significantly as water in your tissues starts to turn to gas.

About Millibar (mbar)

Is mbar the same as hPa?

Yes! 1 mbar = 1 hPa exactly (just different names, same value)

Millibar (mbar):

  • Traditional meteorology unit (1900s-1980s)
  • Still used: Aviation, maritime, older weather services
  • Pilots/mariners: "Set altimeter to 1015 millibars"

Hectopascal (hPa):

  • SI-compliant name (1980s-present)
  • Modern: Weather services worldwide officially use hPa
  • Scientific: Consistent with SI unit system

No conversion needed: 1,013 mbar = 1,013 hPa (identical)

Why two names?: Transition to SI units in 1980s. Chose "hectopascal" because 1 hPa = 1 mbar exactly, making transition seamless. Old term persists in aviation/maritime.

How do I convert mbar to PSI?

Formula: PSI = mbar × 0.0145038

Examples:

  • 1,013 mbar = 14.7 PSI (sea level)
  • 1,000 mbar = 14.5 PSI
  • 900 mbar = 13.05 PSI (storm)
  • 800 mbar = 11.6 PSI
  • 500 mbar = 7.25 PSI (FL180)

mbar to PSI converter →

What is normal atmospheric pressure in mbar?

Standard sea level: 1,013.25 mbar (exactly, by definition)

Typical range: 980-1,050 mbar depending on weather

Pressure variations:

  • Fair weather (high): 1,020-1,040 mbar
  • Normal range: 1,000-1,020 mbar
  • Stormy (low): 980-1,000 mbar
  • Hurricane: <980 mbar

Regional/seasonal: Varies ±30 mbar from standard

Altitude: Decreases ~12 mbar per 100m near sea level

What mbar is considered high or low pressure?

High pressure (anticyclone):

  • Strong high: >1,030 mbar (stable, clear weather)
  • Moderate high: 1,020-1,030 mbar (fair weather)

Normal pressure: 1,005-1,020 mbar

Low pressure (cyclone):

  • Moderate low: 990-1,005 mbar (cloudy, possible rain)
  • Strong low: 970-990 mbar (rain, wind)
  • Very low: <970 mbar (storms, gales)

Extreme low: <920 mbar (major hurricanes/typhoons)

Context matters: 1,000 mbar may be "low" in winter high-pressure region, "high" in tropical area.

Why do pilots still say "millibar" instead of "hectopascal"?

Historical training: Aviation training used mbar for decades International: ICAO (aviation authority) still references millibars Brevity: "Millibar" rolls off tongue easier than "hectopascal" Tradition: Aviation conservative about terminology changes Communication: Older pilots, documents use mbar

Modern transition:

  • Official: ICAO now uses hPa in documents
  • Practice: Pilots use both terms interchangeably
  • Altimeter: Settings shown as "1013 hPa" or "1013 mb"

No confusion: Since 1 mbar = 1 hPa exactly, using either term causes no errors.

Maritime similar: Sailors also prefer "millibar" from tradition.

Conversion Table: Torr to Millibar

Torr (Torr)Millibar (mbar)
0.50.667
11.333
1.52
22.666
56.666
1013.332
2533.331
5066.661
100133.322
250333.306
500666.612
1,0001,333.224

People Also Ask

How do I convert Torr to Millibar?

To convert Torr to Millibar, enter the value in Torr in the calculator above. The conversion will happen automatically. Use our free online converter for instant and accurate results. You can also visit our pressure converter page to convert between other units in this category.

Learn more →

What is the conversion factor from Torr to Millibar?

The conversion factor depends on the specific relationship between Torr and Millibar. You can find the exact conversion formula and factor on this page. Our calculator handles all calculations automatically. See the conversion table above for common values.

Can I convert Millibar back to Torr?

Yes! You can easily convert Millibar back to Torr by using the swap button (⇌) in the calculator above, or by visiting our Millibar to Torr converter page. You can also explore other pressure conversions on our category page.

Learn more →

What are common uses for Torr and Millibar?

Torr and Millibar are both standard units used in pressure measurements. They are commonly used in various applications including engineering, construction, cooking, and scientific research. Browse our pressure converter for more conversion options.

For more pressure conversion questions, visit our FAQ page or explore our conversion guides.

Helpful Conversion Guides

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All Pressure Conversions

Pascal to KilopascalPascal to MegapascalPascal to HectopascalPascal to BarPascal to MillibarPascal to AtmospherePascal to Technical AtmospherePascal to TorrPascal to Millimeter of MercuryPascal to Inch of MercuryPascal to Pound per Square InchPascal to Kilopound per Square InchPascal to Kilogram-force per Square CentimeterPascal to Kilogram-force per Square MeterPascal to Millimeter of Water ColumnPascal to Inch of Water ColumnKilopascal to PascalKilopascal to MegapascalKilopascal to HectopascalKilopascal to BarKilopascal to MillibarKilopascal to AtmosphereKilopascal to Technical AtmosphereKilopascal to TorrKilopascal to Millimeter of MercuryKilopascal to Inch of MercuryKilopascal to Pound per Square InchKilopascal to Kilopound per Square InchKilopascal to Kilogram-force per Square CentimeterKilopascal to Kilogram-force per Square MeterKilopascal to Millimeter of Water ColumnKilopascal to Inch of Water ColumnMegapascal to PascalMegapascal to KilopascalMegapascal to HectopascalMegapascal to BarMegapascal to MillibarMegapascal to AtmosphereMegapascal to Technical AtmosphereMegapascal to TorrMegapascal to Millimeter of MercuryMegapascal to Inch of MercuryMegapascal to Pound per Square InchMegapascal to Kilopound per Square InchMegapascal to Kilogram-force per Square CentimeterMegapascal to Kilogram-force per Square MeterMegapascal to Millimeter of Water ColumnMegapascal to Inch of Water ColumnHectopascal to PascalHectopascal to KilopascalHectopascal to MegapascalHectopascal to BarHectopascal to MillibarHectopascal to AtmosphereHectopascal to Technical AtmosphereHectopascal to TorrHectopascal to Millimeter of MercuryHectopascal to Inch of MercuryHectopascal to Pound per Square InchHectopascal to Kilopound per Square InchHectopascal to Kilogram-force per Square CentimeterHectopascal to Kilogram-force per Square MeterHectopascal to Millimeter of Water ColumnHectopascal to Inch of Water ColumnBar to PascalBar to KilopascalBar to MegapascalBar to HectopascalBar to MillibarBar to AtmosphereBar to Technical AtmosphereBar to TorrBar to Millimeter of MercuryBar to Inch of MercuryBar to Pound per Square InchBar to Kilopound per Square InchBar to Kilogram-force per Square CentimeterBar to Kilogram-force per Square MeterBar to Millimeter of Water ColumnBar to Inch of Water ColumnMillibar to PascalMillibar to KilopascalMillibar to MegapascalMillibar to HectopascalMillibar to BarMillibar to AtmosphereMillibar to Technical AtmosphereMillibar to TorrMillibar to Millimeter of MercuryMillibar to Inch of MercuryMillibar to Pound per Square InchMillibar to Kilopound per Square InchMillibar to Kilogram-force per Square CentimeterMillibar to Kilogram-force per Square MeterMillibar to Millimeter of Water ColumnMillibar to Inch of Water ColumnAtmosphere to PascalAtmosphere to KilopascalAtmosphere to MegapascalAtmosphere to HectopascalAtmosphere to BarAtmosphere to MillibarAtmosphere to Technical AtmosphereAtmosphere to TorrAtmosphere to Millimeter of MercuryAtmosphere to Inch of MercuryAtmosphere to Pound per Square InchAtmosphere to Kilopound per Square InchAtmosphere to Kilogram-force per Square CentimeterAtmosphere to Kilogram-force per Square MeterAtmosphere to Millimeter of Water ColumnAtmosphere to Inch of Water ColumnTechnical Atmosphere to PascalTechnical Atmosphere to KilopascalTechnical Atmosphere to MegapascalTechnical Atmosphere to HectopascalTechnical Atmosphere to BarTechnical Atmosphere to MillibarTechnical Atmosphere to AtmosphereTechnical Atmosphere to Torr

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Verified Against Authority Standards

All conversion formulas have been verified against international standards and authoritative sources to ensure maximum accuracy and reliability.

NIST Reference on Constants, Units and Uncertainty

National Institute of Standards and Technology — Fundamental physical constants and unit conversions

BIPM SI Units

Bureau International des Poids et Mesures — International System of Units (SI) definitions and standards

ISO 80000

International Organization for Standardization — Quantities and units international standards series

Last verified: February 19, 2026