A torr is 1/760 standard atmosphere.
Torrs to Atmospheres Converter — Torr to atm
Convert Torr (Torr) to Atmosphere (atm) using the exact conversion factor (1 torr = 0.0013157895 atmosphere). See the formula, worked examples, conversion table, and common uses.
Torrs to Atmospheres converter
Converter
Pressure Converter
Convert pascals, bars, PSI, atmospheres, mercury columns, water columns, and engineering pressure units.
Context values
Some unit families need one extra value for a physically accurate result.
A standard atmosphere is exactly 101,325 pascals.
Result = input x 133.3223684 / 101325.
Pressure uses the pascal as the base unit.
Reserved above the conversion cards and below the converter.
About Converting Torrs to Atmospheres
Torr and Atmosphere both show up on pressure gauges — psi is standard on US tire and tool specifications, while bar is the everyday pressure unit across most of the rest of the world. Specifically: A torr is 1/760 standard atmosphere, and a standard atmosphere is exactly 101,325 pascals.
Formula
atmospheres = torrs × 0.00131578947368
This factor comes from each unit's defined relationship to the category's base unit: 1 torr equals 133.322368421 base units, and 1 atmosphere equals 101325 base units, so dividing one by the other gives the direct torr-to-atmosphere factor of 0.00131578947368.
Simple example
1 Torr × 0.001315789474 = 0.0013157895 atm
1 torr = 0.0013157895 atmospheres.
Real-world example
35 Torr × 0.001315789474 = 0.0460526316 atm
35 torrs = 0.0460526316 atmospheres.
Conversion table
| Torr (Torr) | Atmosphere (atm) |
|---|---|
| 1 Torr | 0.0013157895 atm |
| 5 Torr | 0.0065789474 atm |
| 10 Torr | 0.0131578947 atm |
| 25 Torr | 0.0328947368 atm |
| 50 Torr | 0.0657894737 atm |
| 100 Torr | 0.1315789474 atm |
Reverse conversion: Atmosphere to Torr
0.0013157895 atm × 760 = 1.00000002 Torr
0.0013157895 atmospheres = 1.00000002 torrs.
torrs = atmospheres × 760
For a page dedicated to this direction, see Atmosphere to Torr.
Understanding the Torr (Torr)
A torr is 1/760 standard atmosphere.
Understanding the Atmosphere
Atmosphere (atm) measures pressure. Defined as exactly 101,325 pascals, originally based on the average atmospheric pressure at mean sea level. It is classified as a non-SI unit accepted for use with the SI.
Where it's used: Widely used internationally in chemistry, meteorology, and diving/aviation contexts alongside the pascal and bar
Uses of the Atmosphere today
- Chemistry (standard conditions are often defined at 1 atm)
- Diving and aviation pressure references
- General reference for everyday atmospheric pressure
Atmosphere — sources
- BIPM SI Brochure — Standard atmosphere listed among non-SI units with a fixed exact value in pascals.
Reserved between the cards and the FAQ so the page stays balanced.
Frequently asked questions
How many atmospheres are in 1 torr?
1 torr equals 0.0013157895 atmospheres, using the exact defined conversion factor rather than an estimate.
How do I convert torr to atmosphere?
Multiply the torr value by 0.001315789474. The converter above does this instantly to whatever precision you set.
How do I convert atmosphere back to torr?
Use the reverse factor: 1 atmosphere equals 760 torrs. You can also use the swap control in the converter above to flip the direction instantly.
What is a torr?
Torr (Torr) is a unit of pressure.
What is a atmosphere?
Atmosphere (atm) measures pressure. Defined as exactly 101,325 pascals, originally based on the average atmospheric pressure at mean sea level. It is classified as a non-SI unit accepted for use with the SI.
Is the torr to atmosphere conversion exact?
Yes. Defined as exactly 101,325 pascals, originally based on the average atmospheric pressure at mean sea level. That fixed definition is what the converter above uses, so any rounding you see is a display choice, not a limitation of the math.