Convert pressure units — Pascal, bar, PSI, atm, Torr, mmHg.
| Unit | Name | Value |
|---|---|---|
| Pa | Pascal | 133.322 |
| kPa | Kilopascal | 0.133322 |
| bar | Bar | 0.00133322 |
| atm | Atmosphere | 0.0013157858 |
| psi | PSI | 0.019336714 |
| inHg | Inch of Mercury | 0.039369949 |
Formula: Inch Hg = Torr × 0.03937
Multiply any torr value by 0.03937 to get inch hg.
Reverse: Torr = Inch Hg × 25.4
Common torr values — factor: 1 Torr = 0.03937 inHg
| Torr (Torr) | Inch Hg (inHg) | Context |
|---|---|---|
| 0.001 Torr | 3.937e-05 inHg | Ultra-high vacuum |
| 0.01 Torr | 0.0003937 inHg | High vacuum |
| 0.1 Torr | 0.003937 inHg | Medium vacuum |
| 1 Torr | 0.03937 inHg | Low vacuum |
| 10 Torr | 0.3937 inHg | Rough vacuum |
| 100 Torr | 3.937 inHg | Near-vacuum |
| 760 Torr | 29.92 inHg | 1 atm / sea level |
| 1,000 Torr | 39.37 inHg | Slight above atm |
| 7,600 Torr | 299.2 inHg | 10 atm |
| 1e+04 Torr | 393.7 inHg | 100 mbar |
| 7.6e+04 Torr | 2,992 inHg | 100 atm |
| 100,000 Torr | 3,937 inHg | 1.3 atm |
| 760,000 Torr | 2.992e+04 inHg | 1,000 atm |
| 1,000,000 Torr | 3.937e+04 inHg | High pressure |
| 10,000,000 Torr | 393,700 inHg | Very high |
1 Torr = 0.03937 inHg. Memorize for instant estimates.
Use 0.0394 as a quick mental multiplier.
Multiply result by 25.4 to recover the original Torr value.
Sets altimeter QNH and reads weather ATIS in inHg — standard US aviation.
Reports barometric pressure in inHg for US television and radio weather.
Measures duct static pressure in inches of water column or inHg in US systems.
Checks HVAC system static pressure and duct leakage in inHg.
Logs surface pressure in inHg for propagation prediction and wx stations.
References inHg barometric pressure when using US-spec nautical instruments.
The torr was named after Evangelista Torricelli, who invented the mercury barometer in 1644. One torr is defined as 1/760 of standard atmospheric pressure (133.322 Pa), and is equal to 1 mmHg at 0°C.
Torr is the standard pressure unit in vacuum science and semiconductor manufacturing. High vacuum systems operate at 10⁻³ to 10⁻⁷ torr. Ultra-high vacuum (used in particle accelerators) reaches below 10⁻¹⁰ torr.
Interesting fact: Torricelli's original barometer experiment used a 1-meter tube of mercury that settled at 760 mm above the reservoir — directly defining the unit that would later bear his name.
Inches of mercury (inHg) is the pressure unit used in US aviation and weather reporting, defined as the pressure exerted by a 1-inch column of mercury (3,386.39 Pa). It has been standard in US aviation since the early 20th century.
US aviation altimeters are set in inHg (standard: 29.92 inHg). US weather broadcasts report barometric pressure in inHg. HVAC engineers in the US use inHg for duct static pressure measurements.
Interesting fact: Pilots set their altimeter to the local QNH (pressure at sea level) in inHg to ensure their altitude reading is accurate — a difference of 0.1 inHg causes an altimeter error of about 100 feet.
Converting torr to inch hg is a common task in engineering, medicine, meteorology, and science. Different industries and countries use different pressure units — PSI in the US, bar in Europe, mmHg in medicine, and pascals in physics — making accurate conversion essential for cross-disciplinary work.
Quick reference: 5 Torr = 0.1968 inHg and 10 Torr = 0.3937 inHg. For the reverse: 1 inHg = 25.4 Torr. The exact factor is 1 Torr = 0.03937 inHg.
All conversions use IEEE 754 double-precision arithmetic, accurate to at least 8 significant figures.