Convert Millimeters of Mercury to Torr (mmHg to Torr)
1 millimeter of mercury (mmHg) equals 1.000000142 torr.
1 mmHg = 1.000000142 Torr
Type in either box. Scientific notation works: 1.5e-3.
Converting a list? Use the bulk millimeter of mercury to torr converter to paste a column from Excel.
How to Convert Millimeter of Mercury to Torr
- 1 mmHg = 1.000000142 Torr
- 1 Torr = 0.9999998575 mmHg
- Example: convert 15 mmHg to Torr: 15 mmHg = 15 × 1.000000142 Torr = 15.00000214 Torr
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
Torr = mmHg × 1.000000142466
Derivation from SI units:
- 1 mmHg = 13 595.1 kg/m³ × 9.80665 m/s² × 0.001 m = 133.322387415 Pa
- 1 Torr = 101325/760 Pa = 133.3223684 Pa (1/760 of a standard atmosphere)
- 1 mmHg = 133.322387415 Pa ÷ 133.3223684211 Pa per Torr = 1.000000142466 Torr
Both units are defined exactly, so the factor is exact. Millimeter of Mercury definition: millimeter of mercury; Torr definition: torr.
Worked examples
- 760 mmHg is 760.0001083 Torr.
760 mmHg × 1.000000142 = 760.0001083 Torr - 1 mmHg equals 1.000000142 Torr.
1 mmHg × 1.000000142 = 1.000000142 Torr
Millimeter of Mercury to Torr conversion table
| Millimeters of Mercury (mmHg) | Torr |
|---|---|
| 1 mmHg | 1.000000142 Torr |
| 5 mmHg | 5.000000712 Torr |
| 10 mmHg | 10.00000142 Torr |
| 20 mmHg | 20.00000285 Torr |
| 40 mmHg | 40.0000057 Torr |
| 60 mmHg | 60.00000855 Torr |
| 70 mmHg | 70.00000997 Torr |
| 80 mmHg | 80.0000114 Torr |
| 90 mmHg | 90.00001282 Torr |
| 100 mmHg | 100.0000142 Torr |
| 110 mmHg | 110.0000157 Torr |
| 120 mmHg | 120.0000171 Torr |
| 130 mmHg | 130.0000185 Torr |
| 140 mmHg | 140.0000199 Torr |
| 160 mmHg | 160.0000228 Torr |
| 180 mmHg | 180.0000256 Torr |
| 200 mmHg | 200.0000285 Torr |
| 300 mmHg | 300.0000427 Torr |
| 500 mmHg | 500.0000712 Torr |
| 750 mmHg | 750.0001068 Torr |
| 760 mmHg | 760.0001083 Torr |
Where it's used
The two units are often treated as identical. They differ by about 0.14 parts per million, which matters only in calibration and metrology.
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 big is the difference between mmHg and torr?
About 0.14 parts per million: 1 mmHg = 1.00000014247 Torr, so for almost every purpose they are interchangeable.
How many torr are in 1 millimeter of mercury?
1 mmHg = 1.000000142 Torr.
How do I convert millimeters of mercury to torr?
Multiply the value in mmHg by 1.000000142. For example, 15 mmHg × 1.000000142 = 15.00000214 Torr.
Is the mmHg to Torr 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, "torr (Torr)".
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 Torr (mmHg to Torr). Retrieved October 18, 2026, from https://scientificconverters.com/pressure/millimeter-of-mercury-to-torr/
IEEE
Scientific Converters, "Convert Millimeters of Mercury to Torr (mmHg to Torr)," scientificconverters.com. Accessed: Oct. 18, 2026. [Online]. Available: https://scientificconverters.com/pressure/millimeter-of-mercury-to-torr/