Convert Torr to Inches of mercury
1 torr is 0.03937 inHg. One torr is exactly 0.0393700689499 inches of mercury.
One torr is 0.039370069 inches of mercury. To convert torr to inches of mercury, multiply by 0.039370069; to go the other way, divide by 0.039370069 or multiply by 25.400006. The factor is exact rather than rounded: it follows from NIST Special Publication 811. Exactly one seven-hundred-and-sixtieth of a standard atmosphere.
Factor checked against the defining standard · How we check
- Torr × 0.039370069
value * 0.03937006894990.039 inHg
1 torr in every pressure unit
| Unit | Value | Exact factor |
|---|---|---|
| pounds per square inch | 0.0193367747 psi | × 0.0193367747046 |
| bars | 0.001333223684 bar | × 0.00133322368421 |
| pascals | 133.3223684 Pa | × 133.322368421 |
| kilopascals | 0.1333223684 kPa | × 0.133322368421 |
| megapascals | 0.0001333223684 MPa | × 0.000133322368421 |
| atmospheres | 0.001315789474 atm | × 0.00131578947368 |
| torr (as entered) | 1 Torr | — |
| inches of mercury | 0.03937006895 inHg | × 0.0393700689499 |
Factors are entered by hand from NIST Special Publication 811 rather than derived from a units library, so the ones that terminate are exact rather than rounded.
How do you convert torr to inches of mercury?
- 1.Take the measurement in torr.
- 2.Multiply by 0.039370069 — that is how many inches of mercury fit in one torr.
- 3.To go back the other way, divide by 0.039370069, or multiply by 25.400006.
Worked example: 25 torr to inches of mercury
- Formula
- Torr × 0.039370069 = inHg
- Arithmetic
- 25 × 0.039370069 = 0.984252 inHg
- Answer
- 25 Torr = 0.984252 inHg
The factor is rounded for display; the figure above is computed from the full value.
Torr to inches of mercury conversion table
| Torr | Inches of mercury |
|---|---|
| 1 Torr | 0.03937 inHg |
| 2 Torr | 0.07874 inHg |
| 3 Torr | 0.11811 inHg |
| 4 Torr | 0.15748 inHg |
| 5 Torr | 0.19685 inHg |
| 6 Torr | 0.23622 inHg |
| 7 Torr | 0.27559 inHg |
| 8 Torr | 0.314961 inHg |
| 9 Torr | 0.354331 inHg |
| 10 Torr | 0.393701 inHg |
| 12 Torr | 0.472441 inHg |
| 15 Torr | 0.590551 inHg |
| 20 Torr | 0.787401 inHg |
| 25 Torr | 0.984252 inHg |
| 50 Torr | 1.968503 inHg |
| 100 Torr | 3.937007 inHg |
| 200 Torr | 7.874014 inHg |
| 300 Torr | 11.811021 inHg |
| 500 Torr | 19.685034 inHg |
| 1000 Torr | 39.370069 inHg |
| 2000 Torr | 78.740138 inHg |
| 5000 Torr | 196.850345 inHg |
| 10000 Torr | 393.700689 inHg |
What is a torr?
Exactly one seven-hundred-and-sixtieth of a standard atmosphere. Within a millionth of a millimetre of mercury, which is what it replaced, and still the unit of vacuum work.
What is an inch of mercury?
The pressure of a one-inch column of mercury at 0 °C, fixed by convention at 3,386.389 pascals. US aviation altimeters and barometers read in it.
How many inches of mercury are in a torr?
One torr is 0.039370069 inches of mercury. Going the other way, one inch of mercury is 25.400006 torr. Both figures come from the same defined relation rather than from a measurement, which is why they are the same today as they were in 1959.
Every pressure unit here
| Unit | Symbol | One of these is |
|---|---|---|
| Pounds per square inch | psi | 6894.7573 pascal |
| Bars | bar | 100000 pascal |
| Pascals | Pa | the base unit |
| Kilopascals | kPa | 1000 pascal |
| Megapascals | MPa | 1000000 pascal |
| Atmospheres | atm | 101325 pascal |
| Torr | Torr | 133.32237 pascal |
| Inches of mercury | inHg | 3386.389 pascal |
Questions people actually ask
- How many inches of mercury are in a torr?
- 0.039370069. The pressure of a one-inch column of mercury at 0 °C, fixed by convention at 3,386.389 pascals. US aviation altimeters and barometers read in it.
- How do I convert inches of mercury back to torr?
- Divide by 0.039370069, or multiply by 25.400006 — they are the same operation.
Other pressure conversions
Inches of mercury to torr — the same conversion the other way.