Convert pressure units — Pascal, bar, PSI, atm, Torr, mmHg.
| Unit | Name | Value |
|---|---|---|
| Pa | Pascal | 101325 |
| kPa | Kilopascal | 101.325 |
| bar | Bar | 1.01325 |
| psi | PSI | 14.695943 |
| Torr | Torr / mmHg | 760.0021 |
| inHg | Inch of Mercury | 29.921244 |
Formula: Inch Hg = Atmosphere × 29.92
Multiply any atmosphere value by 29.92 to get inch hg.
Reverse: Atmosphere = Inch Hg × 0.03342
Common atmosphere values — factor: 1 atm = 29.92 inHg
| Atmosphere (atm) | Inch Hg (inHg) | Context |
|---|---|---|
| 0.001 atm | 0.02992 inHg | Vacuum |
| 0.01 atm | 0.2992 inHg | High vacuum |
| 0.1 atm | 2.992 inHg | Mountain top |
| 0.5 atm | 14.96 inHg | Half atmosphere |
| 1 atm | 29.92 inHg | Sea level |
| 2 atm | 59.84 inHg | 10 m water depth |
| 5 atm | 149.6 inHg | 40 m depth |
| 10 atm | 299.2 inHg | 90 m depth |
| 50 atm | 1,496 inHg | 500 m depth |
| 100 atm | 2,992 inHg | 1 km depth |
| 500 atm | 1.496e+04 inHg | 5 km depth |
| 1,000 atm | 2.992e+04 inHg | 10 km depth |
| 5,000 atm | 149,600 inHg | Deep mantle |
| 1e+04 atm | 299,200 inHg | Very deep mantle |
| 5e+04 atm | 1,496,000 inHg | Diamond formation |
1 atm = 29.92 inHg. Memorize for instant estimates.
Use 29.92 as a quick mental multiplier.
Multiply result by 0.03342 to recover the original atm value.
Uses atmospheres in gas law calculations (PV = nRT) and solubility studies.
Calculates dive depth pressure (every 10 m adds ~1 atm) for dive tables.
Designs diamond anvil cell experiments measuring pressure in thousands of atm.
Specifies autoclave and reactor operating pressures relative to atm.
Estimates metamorphic rock formation pressures in kbar (thousands of atm).
Plans saturation diving operations using atm for depth-pressure calculations.
The atmosphere (atm) is defined as exactly 101,325 pascals — the approximate air pressure at sea level. It was originally defined as the average atmospheric pressure at sea level at 45° latitude, and has been a standard reference since the 17th century.
Atmospheres are used in chemistry (gas laws), scuba diving depth calculations (every 10 m of water ≈ 1 additional atm), and as a convenient reference for extreme pressure comparisons.
Interesting fact: Jupiter's atmosphere has pressures exceeding 1,000 atm at depth. Diamond formation in Earth's mantle requires pressures of 45,000–60,000 atm at depths of 150–200 km.
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 atmosphere 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 atm = 149.6 inHg and 10 atm = 299.2 inHg. For the reverse: 1 inHg = 0.03342 atm. The exact factor is 1 atm = 29.92 inHg.
All conversions use IEEE 754 double-precision arithmetic, accurate to at least 8 significant figures.