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: Pascal = Atmosphere × 1.013e+05
Multiply any atmosphere value by 1.013e+05 to get pascal.
Reverse: Atmosphere = Pascal × 9.8692e-6
Common atmosphere values — factor: 1 atm = 1.013e+05 Pa
| Atmosphere (atm) | Pascal (Pa) | Context |
|---|---|---|
| 0.001 atm | 101.3 Pa | Vacuum |
| 0.01 atm | 1,013 Pa | High vacuum |
| 0.1 atm | 1.013e+04 Pa | Mountain top |
| 0.5 atm | 5.066e+04 Pa | Half atmosphere |
| 1 atm | 101,300 Pa | Sea level |
| 2 atm | 202,600 Pa | 10 m water depth |
| 5 atm | 506,600 Pa | 40 m depth |
| 10 atm | 1,013,000 Pa | 90 m depth |
| 50 atm | 5,066,000 Pa | 500 m depth |
| 100 atm | 10,130,000 Pa | 1 km depth |
| 500 atm | 50,660,000 Pa | 5 km depth |
| 1,000 atm | 101,300,000 Pa | 10 km depth |
| 5,000 atm | 506,600,000 Pa | Deep mantle |
| 1e+04 atm | 1.013e+09 Pa | Very deep mantle |
| 5e+04 atm | 5.066e+09 Pa | Diamond formation |
Atm × 101,325 = Pa. 1 atm = exactly 101,325 Pa.
Using × 100,000 gives 1.3% error — acceptable for estimates.
Pa ÷ 101,325 = atm.
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.
The pascal (Pa) is the SI derived unit of pressure, defined as one newton per square meter. It was named after Blaise Pascal, the 17th-century French mathematician and physicist who studied fluid pressure. The unit was officially adopted by the International System of Units in 1971.
Pascals are used in meteorology (atmospheric pressure ~101,325 Pa), materials science (Young's modulus in GPa), and fluid mechanics. The pascal is very small — standard atmospheric pressure equals 101,325 Pa.
Interesting fact: Blaise Pascal demonstrated in 1648 that atmospheric pressure decreases with altitude by carrying a barometer up the Puy de Dôme mountain, confirming Torricelli's theory of atmospheric pressure.
Converting atmosphere to pascal 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 = 5.066e+05 Pa and 10 atm = 1.013e+06 Pa. For the reverse: 1 Pa = 9.8692e-6 atm. The exact factor is 1 atm = 1.013e+05 Pa.
All conversions use IEEE 754 double-precision arithmetic, accurate to at least 8 significant figures.