Torr to millimeters of mercury
Type a value in torr to see it in millimeters of mercury straight away, or type in the second box to convert back.
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How to use it
- Type the value in the torr box.
- Read the result in millimeters of mercury as you type, and pick the precision you need.
- Swap the direction to convert back, or copy the result.
How it is calculated
mmHg = Torr × 0.9999998575
Multiply the value in torr by 0.9999998575 to get millimeters of mercury.
Example
To convert 25 Torr to millimeters of mercury: 25 × 0.9999998575 = 25 mmHg.
Conversion table
| Torr (Torr) | Millimeters of mercury (mmHg) |
|---|---|
| 1 | 1 |
| 2 | 2 |
| 3 | 3 |
| 5 | 5 |
| 10 | 10 |
| 20 | 20 |
| 25 | 25 |
| 50 | 50 |
| 100 | 100 |
| 250 | 250 |
| 500 | 500 |
| 1,000 | 1,000 |
About the units
- Torr
- Exactly 1/760 of a standard atmosphere, used in vacuum work. It is very close to, but not the same as, one millimeter of mercury.
- Millimeter of mercury
- The pressure of a 1 mm mercury column at the conventional density 13,595.1 kg/m³ and standard gravity: 133.322387415 Pa. Used for blood pressure.
Limits and caveats
- Results are rounded for display and computed with the browser's floating point precision (about 15 significant digits).
- Both unit factors are exact by their official definitions.
Questions about this tool
How many millimeters of mercury are in one torr?
1 Torr = 1 mmHg exactly.
How do I convert torr to millimeters of mercury?
Use mmHg = Torr × 0.9999998575. For example, 25 Torr = 25 mmHg.
How many torr are in one millimeter of mercury?
1 mmHg = 1 Torr.
What is the difference between gauge and absolute pressure?
Gauge pressure is measured from the surrounding air pressure, while absolute pressure starts from a perfect vacuum. These converters change the unit only, so a gauge reading stays a gauge reading.
Are torr and mmHg the same?
Almost. One torr is 101325/760 Pa, about 133.322368 Pa, and one conventional mmHg is 133.322387 Pa, a difference of less than one part per million. For everyday use you can treat them as equal.