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Technical Atmosphere to Torr Converter

Convert technical atmospheres to torr with our free online pressure converter.

Quick Answer

1 Technical Atmosphere = 735.55924 torr

Formula: Technical Atmosphere × conversion factor = Torr

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: December 2025Reviewed by: Sam Mathew, Software Engineer

Technical Atmosphere to Torr Calculator

How to Use the Technical Atmosphere to Torr Calculator:

  1. Enter the value you want to convert in the 'From' field (Technical Atmosphere).
  2. The converted value in Torr 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 Technical Atmosphere to Torr: Step-by-Step Guide

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

Formula:

Torr = at × 735.559

Example Calculation:

1 at = 735.55924 Torr

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?

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📋 Unit Symbols

Copy at & Torr symbols

What is a Technical Atmosphere and a Torr?

1 at = 1 kgf/cm² = 98,066.5 Pa = 98.07 kPa = 0.9807 bar = 0.968 atm = 14.223 PSI = 735.6 mmHg

Symbol: at (from German "technische Atmosphäre")

Also written as: kgf/cm², kg/cm², technical atmosphere, metric atmosphere (not standard atmosphere!)

Physical meaning: Pressure exerted by 1 kilogram-force over 1 square centimeter

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)

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

Common Uses and Applications: technical atmospheres vs torr

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

Common Uses for technical atmospheres

Historical: European engineering (Germany, Austria, Switzerland) pre-1980s. Current: Some Asian countries (China, Russia, Japan) still use occasionally. Older Equipment: Pressure gauges, hydraulic systems from mid-1900s. Legacy Specs: Old engineering drawings, technical manuals.

When to Use 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).

Additional Unit Information

About Technical Atmosphere (at)

What is the difference between "at" and "atm"?

Different units! (Common source of confusion)

at (technical atmosphere):

  • 1 at = 1 kgf/cm² = 98,066.5 Pa
  • Engineering unit based on kilogram-force
  • Symbol: at
  • Historical European engineering

atm (standard atmosphere):

  • 1 atm = 101,325 Pa (exactly, by definition)
  • Based on sea-level atmospheric pressure
  • Symbol: atm
  • Scientific/meteorological standard

Relationship: 1 atm = 1.033 at (about 3% higher)

Why confusion?: Names sound similar, values close (both ≈ atmospheric pressure)

Technical Atmosphere to Atmosphere converter →

How do I convert at to bar?

Formula: bar = at × 0.980665

Quick approximation: 1 at ≈ 1 bar (1.9% difference)

Exact conversions:

  • 1 at = 0.981 bar
  • 2 at = 1.961 bar
  • 5 at = 4.903 bar
  • 10 at = 9.807 bar
  • 100 at = 98.07 bar

Inverse: 1 bar = 1.0197 at

Why so close?: Bar defined (originally) to be close to atmospheric pressure, similar motivation as technical atmosphere

at to Bar converter →

How do I convert at to PSI?

Formula: PSI = at × 14.2233

Examples:

  • 1 at = 14.22 PSI
  • 2 at = 28.45 PSI
  • 5 at = 71.12 PSI (typical air compressor)
  • 10 at = 142.23 PSI
  • 100 at = 1,422.33 PSI (high pressure)

Inverse: 1 PSI = 0.0703 at

Memory aid: 1 at ≈ 14 PSI

at to PSI converter →

How do I convert at to kPa or MPa?

Formula: kPa = at × 98.0665

Examples:

  • 1 at = 98.07 kPa ≈ 0.1 MPa
  • 5 at = 490.3 kPa ≈ 0.5 MPa
  • 10 at = 980.7 kPa ≈ 1 MPa
  • 50 at = 4,903 kPa ≈ 5 MPa
  • 100 at = 9,807 kPa ≈ 10 MPa

Quick rule: Multiply by ~100 to get kPa, divide by ~10 to get MPa

at to kPa converter → at to MPa converter →

Why is this unit not used anymore?

SI adoption (1970s-1980s): Most countries transitioned to SI units (Pa, kPa, MPa, bar)

Problems with technical atmosphere:

  • Not SI-compliant: Based on kilogram-force (gravitational unit)
  • Ambiguity: "kg" is mass, not force (kgf needed for clarity)
  • Gravity dependence: Assumes standard gravity (9.80665 m/s²)
  • Confusion: Easy to confuse with standard atmosphere (atm)

Modern replacements:

  • Bar: 1 at ≈ 1 bar (easy conversion)
  • kPa: 1 at ≈ 100 kPa
  • MPa: For high pressures (1 at = 0.1 MPa)

Still seen in:

  • Older European equipment specifications
  • Chinese industrial standards (some applications)
  • Russian/former Soviet engineering documents
  • Japanese industrial equipment (occasionally)
  • Legacy pressure gauges and instruments

For new designs: Use bar, kPa, or MPa instead of at

Historical importance: Was convenient unit when bar not yet standardized, and provided easy mental approximation to atmospheric pressure.

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.

Conversion Table: Technical Atmosphere to Torr

Technical Atmosphere (at)Torr (Torr)
0.5367.78
1735.559
1.51,103.339
21,471.119
53,677.796
107,355.592
2518,388.981
5036,777.962
10073,555.924
250183,889.81
500367,779.62
1,000735,559.24

People Also Ask

How do I convert Technical Atmosphere to Torr?

To convert Technical Atmosphere to Torr, enter the value in Technical Atmosphere 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 Technical Atmosphere to Torr?

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

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

Learn more →

What are common uses for Technical Atmosphere and Torr?

Technical Atmosphere and Torr 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.

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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 Millimeter of Mercury

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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: December 3, 2025