Convert Torr to Atmospheres
Instantly convert Torr (torr) to Atmospheres (atm) with our free online calculator.
Formula: torr to atm — multiply by 0.00131579
Reference Table
| Torr (torr) | Atmospheres (atm) |
|---|---|
| 1 | 0.00131579 |
| 5 | 0.00657893 |
| 10 | 0.0131579 |
| 25 | 0.0328946 |
| 50 | 0.0657893 |
| 100 | 0.131579 |
How to Convert Torr to Atmospheres
Formula
To convert Torr (torr) to Atmospheres (atm): multiply by 0.00131579
Step-by-Step
- Start with your value in Torr (torr).
- Multiply by 0.00131579 to perform the conversion.
- The result is your value expressed in Atmospheres (atm).
Conversion Factor
1 torr = 0.00131579 atm
Reverse Factor
1 atm = 760.002 torr
Worked Example
Convert 25 Torr to Atmospheres: 25 torr = 0.0328946 atm
About Torr (torr)
A unit of pressure defined as exactly 1/760 of a standard atmosphere (≈ 133.322 Pa). Named after 17th-century physicist Evangelista Torricelli, who in 1643 invented the mercury barometer while studying why suction-lift pumps fail above ~10 m — establishing that the atmosphere itself has weight. The torr is the primary unit in modern vacuum technology and semiconductor fabrication: a "rough vacuum" is ~1 torr, "medium vacuum" 10⁻³ torr (typical of mechanical-pump-only systems), "high vacuum" 10⁻⁶ torr (achievable with turbomolecular pumps, used in mass spectrometry and electron microscopy), and "ultrahigh vacuum" (UHV) 10⁻⁹ torr or lower (semiconductor MBE, surface science, particle accelerators). Manufacturing fabs quote chamber pressures in torr or mTorr (10⁻³ torr) at every process step. Numerically the torr is almost identical to the mmHg (1 torr ≈ 1.000000 mmHg under modern definitions; historically they differed by 0.000015%).
About Atmosphere (atm)
A non-SI unit of pressure defined as exactly 101,325 pascals, corresponding to the standard sea-level atmospheric pressure as adopted by ISO 2533 and the BIPM SI Brochure. Atmospheres are the default reference pressure in physical chemistry (Standard Temperature and Pressure conventions: 1 atm at 273.15 K under IUPAC's 'STP' definition, though IUPAC has since moved to 1 bar STP), in commercial diving (depths are quoted in atmospheres absolute, with each 10 m of seawater adding ~1 atm), and in pressure-sensitive materials research where vapor pressure and saturation data are tabulated at 1 atm. A common pitfall: the "technical atmosphere" (at, 98,066.5 Pa = 1 kgf/cm²) used in some legacy European and Japanese engineering is NOT the same as the standard atmosphere — older pressure-vessel drawings can read 100 at and mean either depending on context. 1 atm = 1.01325 bar = 14.696 psi = 760 mmHg = 760 torr.
Quick Facts
- 1 Torr equals 0.00131579 Atmospheres
- 1 Atmosphere equals 760.002 Torr
- Torr is a unit of pressure
- Atmosphere is a unit of pressure
- This conversion is commonly used in tire inflation, weather reporting, scuba diving, and engineering
Common Torr to Atmosphere Conversions
| Torr (torr) | Atmospheres (atm) |
|---|---|
| 0.1 | 0.000131579 |
| 0.5 | 0.000657893 |
| 1 | 0.00131579 |
| 2 | 0.00263157 |
| 5 | 0.00657893 |
| 10 | 0.0131579 |
| 14.696 | 0.0193368 |
| 15 | 0.0197368 |
| 20 | 0.0263157 |
| 25 | 0.0328946 |
| 50 | 0.0657893 |
| 100 | 0.131579 |
| 150 | 0.197368 |
| 200 | 0.263157 |
| 500 | 0.657893 |
| 1000 | 1.31579 |
Understanding Torr
The Torr (symbol: torr) is a unit of pressure. A unit of pressure defined as exactly 1/760 of a standard atmosphere (≈ 133.322 Pa). Named after 17th-century physicist Evangelista Torricelli, who in 1643 invented the mercury barometer while studying why suction-lift pumps fail above ~10 m — establishing that the atmosphere itself has weight. The torr is the primary unit in modern vacuum technology and semiconductor fabrication: a "rough vacuum" is ~1 torr, "medium vacuum" 10⁻³ torr (typical of mechanical-pump-only systems), "high vacuum" 10⁻⁶ torr (achievable with turbomolecular pumps, used in mass spectrometry and electron microscopy), and "ultrahigh vacuum" (UHV) 10⁻⁹ torr or lower (semiconductor MBE, surface science, particle accelerators). Manufacturing fabs quote chamber pressures in torr or mTorr (10⁻³ torr) at every process step. Numerically the torr is almost identical to the mmHg (1 torr ≈ 1.000000 mmHg under modern definitions; historically they differed by 0.000015%).
Torr are commonly used in tire inflation, weather reporting, scuba diving, and engineering.
Understanding Atmospheres
The Atmosphere (symbol: atm) is a unit of pressure. A non-SI unit of pressure defined as exactly 101,325 pascals, corresponding to the standard sea-level atmospheric pressure as adopted by ISO 2533 and the BIPM SI Brochure. Atmospheres are the default reference pressure in physical chemistry (Standard Temperature and Pressure conventions: 1 atm at 273.15 K under IUPAC's 'STP' definition, though IUPAC has since moved to 1 bar STP), in commercial diving (depths are quoted in atmospheres absolute, with each 10 m of seawater adding ~1 atm), and in pressure-sensitive materials research where vapor pressure and saturation data are tabulated at 1 atm. A common pitfall: the "technical atmosphere" (at, 98,066.5 Pa = 1 kgf/cm²) used in some legacy European and Japanese engineering is NOT the same as the standard atmosphere — older pressure-vessel drawings can read 100 at and mean either depending on context. 1 atm = 1.01325 bar = 14.696 psi = 760 mmHg = 760 torr.
Atmospheres are commonly used in tire inflation, weather reporting, scuba diving, and engineering.
Why Convert Torr to Atmospheres?
Engineers, mechanics, and scientists frequently need to convert pressure between Torr and Atmospheres when working with different measurement standards. Tire pressure, blood pressure readings, weather barometric measurements, and industrial process specifications may all use different pressure units depending on the region or discipline. Reliable conversion prevents equipment misuse and ensures safety.
Frequently Asked Questions
How do I convert Torr to Atmospheres?
A unit of pressure defined as exactly 1/760 of a standard atmosphere (≈ 133. To convert Torr to Atmospheres, multiply by 0.00131579. For example, 25 torr equals 0.0328946 atm.
How many Atmospheres are in 1 Torr?
There are 0.00131579 Atmospheres in 1 Torr.
How many Torr are in 1 Atmosphere?
There are 760.002 Torr in 1 Atmosphere.
What is the formula for Torr to Atmosphere conversion?
The formula is: multiply by 0.00131579. This means 1 torr = 0.00131579 atm.
Is a Torr bigger than a Atmosphere?
Yes. One Torr is larger than one Atmosphere because 1 torr equals 0.00131579 atm, which is less than 1.
When do you need to convert between Torr and Atmospheres?
A non-SI unit of pressure defined as exactly 101,325 pascals, corresponding to the standard sea-level atmospheric pressure as adopted by ISO 2533 and the BIPM SI Brochure. Torr and Atmosphere are both pressure units, so conversion comes up whenever one source of information uses one unit and another uses the other — a classic cross-reference challenge in engineering, trade, travel, and everyday life.