How To Convert Standard Atmosphere to Torr
Formula: torr = atm × 760
Example: Convert 0.85 atm to torr.
0.85 × 760 = 646 torr
To do this conversion by hand, take the pressure value in standard atmospheres.
Multiply it by 760.
The result is the same pressure in torr.
This works because 1 standard atmosphere is defined as exactly 760 torr.
Quick Answer
1 atm = 760 torr
- 0.5 atm = 380 torr
- 1.2 atm = 912 torr
- 2 atm = 1520 torr
Conversion Formula
torr = atm × 760
Recommended (exact definition): this conversion uses the defined relationship between these two pressure units.
In simple words, “torr” is a smaller pressure unit. There are 760 torr in 1 standard atmosphere, so you multiply by 760 to switch from atm to torr.
- Write down your value in atm.
- Multiply by 760.
- Keep the unit as torr.
- Round only if you need fewer decimal places.
Standard atmosphere
A standard atmosphere is a pressure unit based on typical sea-level air pressure. Its symbol is atm.
It became popular in physics and engineering as a practical reference pressure. Later it was standardized so people could compare measurements consistently.
- Reporting pressure in chemistry and gas law problems
- Describing scuba diving pressure levels, like 2 atm, 3 atm
- Comparing lab pressure conditions to “normal” air pressure
- Pressure ratings for sealed containers and equipment
- Reference point when studying boiling points and phase changes
Torr
A torr is a pressure unit often used for vacuum work. Its symbol is torr.
The name comes from Evangelista Torricelli, linked to early studies of air pressure and barometers. It is closely tied to the atmosphere because 760 torr = 1 atm.
- Vacuum chambers and vacuum pumps
- Thin film coating systems, like sputtering and evaporation
- Semiconductor and lab process equipment
- Measuring low pressures in physics experiments
- Specifications for vacuum gauges and instruments
Is this Conversion of Standard Atmosphere To Torr Accurate?
Yes. This conversion is exact because it is based on how the units are defined. By definition, 1 atm = 760 torr, so the multiplication factor does not change.
Our converter uses this fixed relationship and the standard definition of the standard atmosphere as 101,325 pascals, which keeps the result consistent for study, engineering, and lab work. Any differences you might see in real measurements usually come from the accuracy of the gauge, calibration, temperature effects, or local conditions, not from the conversion itself. For more details, see our accuracy standards.
Real Life Examples
Here are practical examples showing where atm to torr conversions are useful and what the numbers look like.
- Vacuum oven setting: A vacuum oven is set to 0.2 atm. In torr, that is
0.2 × 760 = 152 torr, which helps if the gauge is labeled in torr. - Rough vacuum for drying: A process calls for 0.05 atm. Converting gives
0.05 × 760 = 38 torr, a common rough-vacuum region. - Reduced pressure distillation: A lab note says “work at 0.3 atm.” In torr, that is
0.3 × 760 = 228 torr, making it easy to match a vacuum controller reading. - Leak check comparison: A device drops from 1.00 atm to 0.98 atm. The pressure drop is
(1.00 − 0.98) × 760 = 15.2 torr, useful for quick leak analysis. - Pressure chamber test: A product is tested at 2.5 atm. In torr, that is
2.5 × 760 = 1900 torr, which may match a legacy instrument scale. - Gas cylinder regulator reference: A small setup is regulated to 1.1 atm absolute. In torr, that is
1.1 × 760 = 836 torr. - Vacuum gauge cross-check: If a gauge reads 600 torr, that equals
600 ÷ 760 ≈ 0.7895 atm, helping you compare with specs written in atm.
Quick Tips
- Remember the key fact, 1 atm = 760 torr.
- To go from atm to torr, multiply by 760.
- To go from torr to atm, divide by 760.
- Common checkpoints: 0.5 atm = 380 torr, 2 atm = 1520 torr.
- If your answer seems off, check if the pressure is absolute or gauge, and confirm the unit on the instrument.
- Keep extra decimals only when you really need them, most lab work is fine with 2 to 3 decimals.