UnitsConverter

Torr to Atmosphere Converter

Convert torr to atmospheres with our free online pressure converter.

Quick Answer

1 Torr = 0.001316 atmospheres

Formula: Torr × conversion factor = Atmosphere

Use the calculator below for instant, accurate conversions.

Our Accuracy Guarantee

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: December 2025Reviewed by: Sam Mathew, Software Engineer

Torr to Atmosphere Calculator

How to Use the Torr to Atmosphere Calculator:

  1. Enter the value you want to convert in the 'From' field (Torr).
  2. The converted value in Atmosphere 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.
Share:

How to Convert Torr to Atmosphere: Step-by-Step Guide

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

Formula:

atm = Torr × 0.00131579

Example Calculation:

1 Torr = 0.001316 atm

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.

Need to convert to other pressure units?

View all Pressure conversions →
📊 Pressure Table

Print-friendly conversion reference

📋 Unit Symbols

Copy Torr & atm symbols

What is a Torr and a Atmosphere?

1 Torr = 1/760 atm (exactly) = 133.322 Pa = 1.333 mbar ≈ 1 mmHg (0.000015% difference)

Key relationships:

  • 760 Torr = 1 atmosphere (exactly)
  • 1 Torr ≈ 1 mmHg (virtually identical)
  • 1 mTorr = 0.001 Torr (millitorr)

1 atm = 101,325 Pa = 101.325 kPa = 14.696 PSI = 1.01325 bar = 760 mmHg = 760 Torr = 29.92 inHg

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

Common Uses and Applications: torr vs atmospheres

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

Common Uses for torr

Vacuum Technology: High vacuum pumps, vacuum chambers, thin-film deposition. Physics Laboratories: Pressure measurement in evacuated systems. Chemistry: Vapor pressure measurements, distillation processes. Medicine: Blood pressure (often interchangeable with mmHg).

When to Use atmospheres

Chemistry: Gas laws (PV=nRT), reaction conditions, vapor pressures, standard conditions (STP). Diving: Depth pressure calculations (1 atm per 10m/33ft water). Physics: Standard reference pressure for equations, thermodynamics. Engineering: High-pressure systems, pressure vessels, gas storage.

Additional Unit Information

About Torr (Torr)

What is the difference between Torr and mmHg?

Almost identical: 1 Torr ≈ 1 mmHg (difference < 0.000015%)

Torr: Defined as exactly 1/760 atmosphere (by definition) mmHg: Based on mercury density at 0°C and standard gravity

Practical usage:

  • Vacuum technology: Prefers Torr (more precise definition)
  • Medicine: Prefers mmHg (traditional, familiar)
  • Chemistry: Uses both interchangeably

Conversion: For all practical purposes, treat them as equal.

Torr to mmHg converter →

How many torr in 1 atmosphere?

1 atm = 760 Torr (exactly, by definition)

Examples:

  • 2 atm = 1,520 Torr
  • 0.5 atm = 380 Torr
  • 0.001 atm = 0.76 Torr
  • 10⁻⁶ atm = 0.00076 Torr = 0.76 mTorr (millitorr)

Atmosphere to Torr converter →

How do I convert Torr to PSI?

Formula: PSI = Torr × 0.0193368

Examples:

  • 760 Torr = 14.7 PSI (1 atmosphere)
  • 120 Torr = 2.32 PSI (systolic blood pressure)
  • 80 Torr = 1.55 PSI (diastolic blood pressure)
  • 1 Torr = 0.0193 PSI
  • 0.001 Torr = 0.0000193 PSI

Torr to PSI converter →

How do I convert Torr to Pascals?

Formula: Pa = Torr × 133.322

Examples:

  • 1 Torr = 133.322 Pa = 0.133 kPa
  • 760 Torr = 101,325 Pa = 101.325 kPa (1 atm)
  • 0.001 Torr (1 mTorr) = 0.133 Pa
  • 10⁻⁶ Torr = 0.000133 Pa

Torr to Pascal converter →

Why use Torr instead of mmHg in vacuum technology?

Torr advantages:

  • Exact definition: 1/760 atm (no ambiguity)
  • Independent: Not dependent on mercury properties
  • Standard: Agreed upon by vacuum scientists
  • Precision: Better defined for scientific work

mmHg issues:

  • Temperature dependent: Mercury density varies
  • Gravity dependent: Varies slightly with location
  • Less precise: For ultra-high vacuum measurements

In practice: Both work fine for most applications, but Torr is preferred in vacuum physics and engineering.

About Atmosphere (atm)

How many PSI is 1 atmosphere?

1 atm = 14.696 PSI (often rounded to 14.7 PSI)

Examples:

  • 2 atm = 29.4 PSI (10m dive depth)
  • 3 atm = 44.1 PSI (20m dive depth)
  • 10 atm = 147 PSI (compressed air)
  • 100 atm = 1,470 PSI (gas cylinder)

Atmosphere to PSI converter →

How many atmospheres in a bar?

1 bar = 0.986923 atm (approximately 1 atm, ~1.3% difference)

Conversion:

  • 1 atm = 1.01325 bar
  • 10 atm = 10.1325 bar
  • 100 atm = 101.325 bar
  • 200 atm = 202.65 bar (scuba tank)

Why different?: Bar defined as exactly 100,000 Pa; atm defined as 101,325 Pa.

Atmosphere to Bar converter →

What pressure is 2 atmospheres?

2 atm = 202,650 Pa = 202.65 kPa = 29.4 PSI = 2.026 bar = 1,520 mmHg

Physical meaning:

  • Diving 10 meters (33 feet) underwater
  • Absolute pressure at 10m depth
  • Double the surface atmospheric pressure
  • Pressure inside a pressure cooker

How do I calculate diving depth pressure?

Formula: Total Pressure (atm) = 1 + (Depth in meters ÷ 10)

Or: Total Pressure (atm) = 1 + (Depth in feet ÷ 33)

Examples:

  • 10m (33ft): 1 + (10÷10) = 2 atm
  • 20m (66ft): 1 + (20÷10) = 3 atm
  • 30m (99ft): 1 + (30÷10) = 4 atm
  • 40m (131ft): 1 + (40÷10) = 5 atm

Note: Freshwater calculation uses 10.3m; saltwater 10m per atmosphere.

What is STP in chemistry?

STP (Standard Temperature and Pressure):

  • Pressure: 1 atm = 101,325 Pa = 100 kPa (IUPAC uses 100 kPa)
  • Temperature: 0°C = 273.15 K

Purpose: Reference conditions for gas law calculations

Molar volume at STP: 22.414 L/mol (IUPAC: 22.711 L/mol at 100 kPa)

SATP (Standard Ambient):

  • Pressure: 1 atm = 101,325 Pa
  • Temperature: 25°C = 298.15 K
  • Molar volume: 24.465 L/mol

More commonly used in modern chemistry.

Conversion Table: Torr to Atmosphere

Torr (Torr)Atmosphere (atm)
0.50.001
10.001
1.50.002
20.003
50.007
100.013
250.033
500.066
1000.132
2500.329
5000.658
1,0001.316

People Also Ask

How do I convert Torr to Atmosphere?

To convert Torr to Atmosphere, 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 Atmosphere?

The conversion factor depends on the specific relationship between Torr and Atmosphere. 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 Atmosphere back to Torr?

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

Learn more →

What are common uses for Torr and Atmosphere?

Torr and Atmosphere 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

Learn more about unit conversion with our comprehensive guides:

📚 How to Convert Units

Step-by-step guide to unit conversion with practical examples.

🔢 Conversion Formulas

Essential formulas for pressure and other conversions.

⚖️ Metric vs Imperial

Understand the differences between measurement systems.

⚠️ Common Mistakes

Learn about frequent errors and how to avoid them.

View All Guides →

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

Other Pressure Units and Conversions

Explore other pressure units and their conversion options:

View all pressure units →

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: December 3, 2025