Inches of mercury (inHg) to Torr (Torr) Conversion
Inches of mercury
The inch of mercury (inHg) is a unit of pressure equal to the pressure exerted by a column of mercury 1 inch (25.4 mm) high — approximately 3,386.39 Pa or 0.0334 atm. It is used in US aviation for altimeter settings (standard pressure is 29.92 inHg) and in US weather reports for barometric pressure. Pilots set their altimeters in inHg based on local barometric pressure to ensure accurate altitude readings.
Torr
The torr is a unit of pressure named after Evangelista Torricelli, the Italian physicist who invented the mercury barometer in 1643. One torr is defined as exactly 1/760 of a standard atmosphere (approximately 133.322 Pa). Numerically nearly identical to the millimetre of mercury (mmHg), it differs by less than 0.000015%. The torr is used in vacuum science and engineering: rough vacuum is 1–100 torr, fine vacuum 10⁻³–1 torr, and ultra-high vacuum below 10⁻⁹ torr.
| Inches of mercury (inHg) | Torr (Torr) |
|---|---|
| 0.1 inHg | 2.54 Torr |
| 1 inHg | 25.40 Torr |
| 2 inHg | 50.80 Torr |
| 3 inHg | 76.20 Torr |
| 5 inHg | 127.00 Torr |
| 10 inHg | 254.00 Torr |
| 20 inHg | 508.0001 Torr |
| 30 inHg | 762.0001 Torr |
| 50 inHg | 1,270.0002 Torr |
| 100 inHg | 2,540.0004 Torr |
| 1000 inHg | 25,400.0036 Torr |
Frequently Asked Questions (FAQ)
How many torr are in 1 inches of mercury?
1 inches of mercury (inHg) is exactly 25.400 torr (Torr).
How do I convert inches of mercury to torr?
Multiply the value in inches of mercury by 25.400 to get the result in torr. Or use the converter above — type any number and see the result instantly.