Torr to Atm Converter - Convert Torrs to Atmospheres
Free torr to atm converter for converting between torrs (Torr) and standard atmospheres (atm). Our converter provides instant, accurate pressure conversions with real-time bidirectional calculation. Perfect for scientific research, vacuum measurements, barometric pressure readings, and engineering applications. Simple, fast, and reliable pressure unit conversion.
Last updated: January 24, 2026
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Conversion Formula:
1 Torr = 1/760 atm ≈ 0.00131579 atm
1 atm = 760 Torr
Enter a value in either field to see the conversion. The calculator updates in real-time as you type. Note: 1 Torr is approximately equal to 1 mmHg (millimeter of mercury).
Conversion Result:
800.00 Torr = 1.052632 atm
Approximately 800.00 mmHg (millimeters of mercury)
Understanding Torr and Atmosphere
Definition
1 Torr = 1/760 atm
A torr is a unit of pressure named after Evangelista Torricelli, an Italian physicist and mathematician. One torr is defined as exactly 1/760 of a standard atmosphere. It's approximately equal to 1 millimeter of mercury (mmHg) and is commonly used in vacuum measurements and barometric pressure readings.
- Used in vacuum systems
- Common in scientific research
- Approximately equal to 1 mmHg
Definition
1 atm = 760 Torr
A standard atmosphere (atm) is a unit of pressure defined as exactly 101,325 pascals. It represents the average atmospheric pressure at sea level. One atmosphere equals 760 Torr or 760 millimeters of mercury. It's commonly used as a reference pressure in scientific and engineering applications.
- Standard reference pressure
- Used in meteorology
- Common in engineering
Quick Example Result
Converting 800 torrs to atmospheres:
Input
800 Torr
Result
1.0526 atm
How Our Torr to Atm Converter Works
Our torr to atm converter provides instant, accurate conversion between torrs and standard atmospheres. The conversion uses the exact relationship: 1 Torr = 1/760 atm, which means 1 atm = 760 Torr. This is an exact conversion factor with no rounding, making it precise for scientific and engineering applications.
Conversion Formula
1 Torr = 1/760 atm ≈ 0.00131579 atm1 atm = 760 TorrTo convert Torr to atm: atm = Torr ÷ 760To convert atm to Torr: Torr = atm × 760The conversion factor 1/760 comes from the definition of a torr as exactly 1/760 of a standard atmosphere. This is an exact relationship, not an approximation, making conversions precise and reliable.
Torr and mmHg Relationship
An important relationship to understand is that 1 Torr is approximately equal to 1 millimeter of mercury (mmHg). While they are not exactly equal, the difference is extremely small (less than 0.0002%), making them essentially equivalent for most practical purposes.
Key Relationships:
- • 1 Torr = 0.9999998575337 mmHg: Almost exactly equal
- • 1 mmHg = 1.0000001424663203 Torr: Essentially equivalent
- • For practical purposes: 1 Torr ≈ 1 mmHg (with accuracy up to 6 significant figures)
- • Both represent: Pressure of a 1 mm column of mercury
Historical Context
The torr unit is named after Evangelista Torricelli, an Italian physicist and mathematician who invented the barometer in 1643. The first barometers consisted of mercury inside a vertical glass tube, which led to the natural pressure unit of millimeters of mercury (mmHg). The torr was later defined as exactly 1/760 of a standard atmosphere to provide a more precise and standardized unit.
Practical Applications
Torr to atmosphere conversion is essential in many scientific and engineering applications. Scientists need to convert between these units when working with vacuum systems, barometric pressure measurements, and comparing pressure values from different sources or standards.
Common Use Cases:
- • Vacuum systems: Measuring and converting vacuum pressures in scientific and industrial equipment
- • Barometric pressure: Converting barometric readings between different unit systems
- • Scientific research: Converting pressure measurements in laboratory experiments
- • Meteorology: Converting atmospheric pressure readings for weather analysis
- • Industrial processes: Converting pressure specifications in manufacturing and process control
- • Medical applications: Converting pressure measurements in medical devices and equipment
Conversion to Other Pressure Units
While our calculator focuses on torr to atm conversion, torr can also be converted to many other pressure units. Here are some common conversions (rounded to 6 decimal places):
Torr to Other Units:
- • 1 Torr ≈ 133.322368 Pa (pascals)
- • 1 Torr ≈ 1.333223 hPa (hectopascals)
- • 1 Torr ≈ 0.133322 kPa (kilopascals)
- • 1 Torr ≈ 0.019337 psi (pounds per square inch)
- • 1 Torr ≈ 0.001333 bar
- • 1 Torr ≈ 0.039370 inHg (inches of mercury)
Sources & References
- NIST Special Publication 811 - Guide for the Use of the International System of Units (SI)Official reference for pressure unit definitions and conversions
- IUPAC Gold Book - Compendium of Chemical TerminologyStandard definitions for pressure units including torr and atmosphere
- BIPM - International Bureau of Weights and MeasuresAuthoritative source for unit definitions and standards
Need help with other pressure conversions? Check out our pressure converter for more unit options.
Get Custom Calculator for Your PlatformTorr to Atm Converter Examples
Input:
- Pressure: 800 Torr
- Conversion factor: 1/760
- Target unit: Atmospheres (atm)
Calculation:
- Step 1: Identify pressure: 800 Torr
- Step 2: Apply conversion: 800 × (1/760)
- Step 3: Calculate result: 800 ÷ 760 = 1.0526 atm
Result: 800 Torr equals 1.0526 atmospheres
This conversion uses the exact relationship: 1 Torr = 1/760 atm. The result is precise with no rounding error, making it suitable for scientific and engineering applications.
760 Torr to atm
760 ÷ 760
= 1.0 atm
2.5 atm to Torr
2.5 × 760
= 1,900 Torr
500 Torr to atm
500 ÷ 760
= 0.6579 atm
0.5 atm to Torr
0.5 × 760
= 380 Torr
Frequently Asked Questions
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