mmHg to atm Converter
Created by: Sophia Bennett
Last updated:
To convert mmHg to atm, divide by 760, because one standard atmosphere is exactly 760 mmHg. So 760 mmHg is 1 atm, 380 mmHg is 0.5 atm and 750 mmHg is 0.987 atm. To convert atm to mmHg, multiply by 760. The converter also gives the pressure in kPa, torr and psi.
mmHg to atm Converter
Conversion1 mmHg = 0.001316 atm. Switch direction to convert atmospheres to millimeters of mercury.
mmHg to atm conversion chart
atm = mmHg ÷ 760.
| Millimeters of mercury (mmHg) | Atmospheres (atm) |
|---|---|
| 1 mmHg | 0.001316 atm |
| 10 mmHg | 0.01316 atm |
| 50 mmHg | 0.06579 atm |
| 80 mmHg | 0.1053 atm |
| 100 mmHg | 0.1316 atm |
| 120 mmHg | 0.1579 atm |
| 200 mmHg | 0.2632 atm |
| 250 mmHg | 0.3289 atm |
| 300 mmHg | 0.3947 atm |
| 380 mmHg | 0.5 atm |
| 400 mmHg | 0.5263 atm |
| 500 mmHg | 0.6579 atm |
| 600 mmHg | 0.7895 atm |
| 700 mmHg | 0.9211 atm |
| 720 mmHg | 0.9474 atm |
| 740 mmHg | 0.9737 atm |
| 742 mmHg | 0.9763 atm |
| 750 mmHg | 0.9868 atm |
| 760 mmHg | 1 atm |
| 770 mmHg | 1.0132 atm |
| 780 mmHg | 1.0263 atm |
| 800 mmHg | 1.0526 atm |
| 1,000 mmHg | 1.3158 atm |
| 1,520 mmHg | 2 atm |
| 2,280 mmHg | 3 atm |
| Atmospheres (atm) | Millimeters of mercury (mmHg) |
|---|---|
| 0.1 atm | 76 mmHg |
| 0.25 atm | 190 mmHg |
| 0.5 atm | 380 mmHg |
| 0.75 atm | 570 mmHg |
| 0.9 atm | 684 mmHg |
| 0.95 atm | 722 mmHg |
| 1 atm | 760 mmHg |
| 1.5 atm | 1,140 mmHg |
| 2 atm | 1,520 mmHg |
| 2.5 atm | 1,900 mmHg |
| 3 atm | 2,280 mmHg |
| 5 atm | 3,800 mmHg |
| 10 atm | 7,600 mmHg |
How to convert mmHg to atm
atm = mmHg ÷ 760
mmHg = atm × 760
The standard atmosphere is defined as 101,325 Pa, the pressure that supports a 760 mm column of mercury. So 760 mmHg is exactly 1 atm by definition, and the conversion is a single division.
Worked examples
- Convert 380 mmHg to atm: 380 ÷ 760 = 0.5 atm.
- Convert 742 mmHg to atm: 742 ÷ 760 = 0.976 atm.
- Convert 2.5 atm to mmHg: 2.5 × 760 = 1,900 mmHg.
Frequently Asked Questions
How do you convert mmHg to atm?
Divide mmHg by 760, because one standard atmosphere is defined as 760 mmHg. 380 mmHg ÷ 760 = 0.5 atm and 750 mmHg = 0.987 atm. To convert atm to mmHg, multiply by 760.
What is 760 mmHg in atm?
760 mmHg is exactly 1 atm, the standard atmospheric pressure at sea level.
What is the mmHg to atm conversion factor?
1 mmHg = 1/760 atm = 0.0013158 atm. In SI units, 1 mmHg = 133.322 Pa and 1 atm = 101,325 Pa.
Is mmHg the same as torr?
Almost. A torr is defined as exactly 1/760 atm, and a conventional mmHg is 133.322387 Pa. They differ by less than one part in seven million, so they are interchangeable for chemistry and medicine.
How do I convert mmHg to atm in a gas law problem?
Convert pressure to atm before using R = 0.08206 L·atm/(mol·K) in PV = nRT. For example, a gas at 742 mmHg is 742 ÷ 760 = 0.976 atm.
Why is blood pressure measured in mmHg?
Early blood pressure gauges used a column of mercury, and the unit stuck. A reading of 120/80 mmHg is 0.158/0.105 atm above atmospheric pressure, which is why medicine keeps the more readable mmHg.
Sources and References
- NIST Special Publication 811. Appendix B: 1 atm = 101 325 Pa (exact); 1 mmHg (conventional) = 133.3224 Pa; 1 torr = 101 325/760 Pa.