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: PSI = Atmosphere × 14.7
Multiply any atmosphere value by 14.7 to get psi.
Reverse: Atmosphere = PSI × 0.06805
Common atmosphere values — factor: 1 atm = 14.7 psi
| Atmosphere (atm) | PSI (psi) | Context |
|---|---|---|
| 0.001 atm | 0.0147 psi | Vacuum |
| 0.01 atm | 0.147 psi | High vacuum |
| 0.1 atm | 1.47 psi | Mountain top |
| 0.5 atm | 7.348 psi | Half atmosphere |
| 1 atm | 14.7 psi | Sea level |
| 2 atm | 29.39 psi | 10 m water depth |
| 5 atm | 73.48 psi | 40 m depth |
| 10 atm | 147 psi | 90 m depth |
| 50 atm | 734.8 psi | 500 m depth |
| 100 atm | 1,470 psi | 1 km depth |
| 500 atm | 7,348 psi | 5 km depth |
| 1,000 atm | 1.47e+04 psi | 10 km depth |
| 5,000 atm | 7.348e+04 psi | Deep mantle |
| 1e+04 atm | 147,000 psi | Very deep mantle |
| 5e+04 atm | 734,800 psi | Diamond formation |
1 atm = 14.7 psi. Memorize for instant estimates.
Use 14.7 as a quick mental multiplier.
Multiply result by 0.06805 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.
PSI (pounds per square inch) is the primary pressure unit in the United States, UK, and other countries using Imperial measures. It equals the force of one pound-force applied over one square inch of area (6,894.76 Pa).
PSI is used for tire pressure (car: 30–35 psi, truck: 80–120 psi), blood pressure measurement in the US, boiler pressure ratings, and hydraulic system specifications in American engineering.
Interesting fact: The deepest ocean dive by a human (Victor Vescovo, 2019, 10,928 m) would have experienced about 15,900 psi of external pressure on the submersible hull.
Converting atmosphere to psi 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 = 73.48 psi and 10 atm = 147 psi. For the reverse: 1 psi = 0.06805 atm. The exact factor is 1 atm = 14.7 psi.
All conversions use IEEE 754 double-precision arithmetic, accurate to at least 8 significant figures.