Convert Millimeters of Mercury to psi (mmHg to psi)
1 millimeter of mercury (mmHg) equals 0.01933677746 psi.
1 mmHg = 0.01933677746 psi
Type in either box. Scientific notation works: 1.5e-3.
Converting a list? Use the bulk millimeter of mercury to psi converter to paste a column from Excel.
How to Convert Millimeter of Mercury to psi
- 1 mmHg = 0.01933677746 psi
- 1 psi = 51.7149252 mmHg
- Example: convert 15 mmHg to psi: 15 mmHg = 15 × 0.01933677746 psi = 0.2900516619 psi
Reference conditions. mmHg: Conventional mercury column: ρ = 13 595.1 kg/m³ and gₙ = 9.80665 m/s² (≈ mercury at 0 °C / 32 °F).
Formula
psi = mmHg × 0.01933677745946
or psi = mmHg ÷ 51.71492520387
Derivation from SI units:
- 1 mmHg = 13 595.1 kg/m³ × 9.80665 m/s² × 0.001 m = 133.322387415 Pa
- 1 psi = 1 lbf/in² = (0.45359237 kg × 9.80665 m/s²) ÷ (0.0254 m)² = 6894.757293168 Pa
- 1 mmHg = 133.322387415 Pa ÷ 6894.757293168 Pa per psi = 0.01933677745946 psi
Both units are defined exactly, so the factor is exact. Millimeter of Mercury definition: millimeter of mercury; psi definition: psi.
Worked examples
- A blood-pressure cuff inflated to 300 mmHg is at 5.801033238 psi.
300 mmHg × 0.01933677746 = 5.801033238 psi - A vacuum of 25 mmHg below atmosphere is 0.4834194365 psi.
25 mmHg × 0.01933677746 = 0.4834194365 psi
Millimeter of Mercury to psi conversion table
| Millimeters of Mercury (mmHg) | psi |
|---|---|
| 1 mmHg | 0.01933677746 psi |
| 5 mmHg | 0.0966838873 psi |
| 10 mmHg | 0.1933677746 psi |
| 20 mmHg | 0.3867355492 psi |
| 40 mmHg | 0.7734710984 psi |
| 60 mmHg | 1.160206648 psi |
| 70 mmHg | 1.353574422 psi |
| 80 mmHg | 1.546942197 psi |
| 90 mmHg | 1.740309971 psi |
| 100 mmHg | 1.933677746 psi |
| 110 mmHg | 2.127045521 psi |
| 120 mmHg | 2.320413295 psi |
| 130 mmHg | 2.51378107 psi |
| 140 mmHg | 2.707148844 psi |
| 160 mmHg | 3.093884394 psi |
| 180 mmHg | 3.480619943 psi |
| 200 mmHg | 3.867355492 psi |
| 300 mmHg | 5.801033238 psi |
| 500 mmHg | 9.66838873 psi |
| 750 mmHg | 14.50258309 psi |
| 760 mmHg | 14.69595087 psi |
Where it's used
Converting mmHg to psi is common in biomedical device design and when comparing vacuum gauges calibrated in different units.
Millimeter of Mercury to other pressure units
| Conversion | 1 mmHg equals |
|---|---|
| millimeter of mercury to pascal | 133.3223874 Pa |
| millimeter of mercury to kilopascal | 0.1333223874 kPa |
| millimeter of mercury to megapascal | 0.0001333223874 MPa |
| millimeter of mercury to psi | 0.01933677746 psi |
| millimeter of mercury to bar | 0.001333223874 bar |
| millimeter of mercury to millibar | 1.333223874 mbar |
| millimeter of mercury to decibar | 0.01333223874 dbar |
| millimeter of mercury to torr | 1.000000142 Torr |
| millimeter of mercury to millimeter of water | 13.5951 mmH₂O |
| millimeter of mercury to centimeter of water | 1.35951 cmH₂O |
| millimeter of mercury to inch of water | 0.5352401575 inH₂O |
| millimeter of mercury to inch of water (60 °F) | 0.5357755482 inH₂O (60 °F) |
| millimeter of mercury to inch of mercury | 0.03937007874 inHg |
| millimeter of mercury to atmosphere | 0.001315789661 atm |
| millimeter of mercury to barye | 1333.223874 Ba |
Frequently asked questions
How many psi is 120 mmHg?
120 mmHg = 2.32 psi.
How many psi are in 1 millimeter of mercury?
1 mmHg = 0.01933677746 psi.
How do I convert millimeters of mercury to psi?
Multiply the value in mmHg by 0.01933677746, or divide it by 51.7149252. For example, 15 mmHg × 0.01933677746 = 0.2900516619 psi.
Is the mmHg to psi conversion exact?
Yes. Both units are defined exactly, so the ratio is exact; its decimal form does not terminate and is shown here to 10 significant figures (more with the precision selector).
Sources
- Guide for the Use of the International System of Units (SI), NIST Special Publication 811, 2008 Edition, National Institute of Standards and Technology , Appendix B.8, "millimeter of mercury, conventional (mmHg)".
- Guide for the Use of the International System of Units (SI), NIST Special Publication 811, 2008 Edition, National Institute of Standards and Technology , Appendix B.8, "pound-force per square inch (psi)".
Last reviewed: . Factors are stored exactly and computed with 50-digit decimal arithmetic. See how we verify conversion factors.
Cite this page
APA
Scientific Converters. (2026, October 15). Convert Millimeters of Mercury to psi (mmHg to psi). Retrieved October 18, 2026, from https://scientificconverters.com/pressure/millimeter-of-mercury-to-psi/
IEEE
Scientific Converters, "Convert Millimeters of Mercury to psi (mmHg to psi)," scientificconverters.com. Accessed: Oct. 18, 2026. [Online]. Available: https://scientificconverters.com/pressure/millimeter-of-mercury-to-psi/