Standard Atmospheres to PSI (atm to psi)
1 standard atmosphere equals 14.69594878 pounds per square inch (rounded).
How to convert standard atmospheres to pounds per square inch
To convert standard atmospheres to pounds per square inch, multiply the number of standard atmospheres by 14.69594878. The factor is rounded to 10 significant digits. To go the other way, multiply pounds per square inch by 0.06804596391 (rounded).
pounds per square inch = standard atmospheres × 14.69594878
Example: 10 standard atmospheres = 146.9594878 pounds per square inch.
About these units
Standard Atmosphere (atm)
Exactly 101,325 pascals, the average pressure of the atmosphere at sea level.
A column of mercury about 76 cm tall was Torricelli's measure of the air, and the standard atmosphere began as exactly that: the pressure of 760 mm of mercury at 0 degrees Celsius under standard gravity. It was used as a reference for physical and chemical properties, and the Celsius scale set 100 degrees as the boiling point of water at that pressure.
In 1954 the 10th CGPM confirmed the standard atmosphere as exactly 1,013,250 dynes per square centimeter, which is 101,325 pascals, a definition that no longer depends on the properties of any substance.
In practice one atmosphere is about 1.01325 bar, 760 mmHg, 14.696 psi or 29.92 inHg, and roughly the pressure of 10.33 meters of water. Chemistry splits on it: until 1982 standard temperature and pressure used 1 atm, but that year IUPAC recommended a standard pressure of exactly 100 kPa instead.
1 standard atmosphere = 101,325 pascals (exactly).
Sources: Wikipedia: Standard atmosphere (unit); Wikipedia: Atmospheric pressure; Wikipedia: Evangelista Torricelli
Pound Per Square Inch (psi)
About 6,894.757 pascals. The common unit for tire pressure, hydraulics and gas pipelines in the US.
Unlike most pressure units, psi has no namesake: it simply spells out its own definition, one pound-force acting on one square inch, and it is based on avoirdupois units. Used mainly in the United States, it is about 6.895 kilopascals.
The letters after the unit matter. Psia is measured against a vacuum, while psig is measured against the surrounding air, so at sea level, where the atmosphere is about 14.7 psi, you add that amount to a gauge reading to get an absolute one. A bicycle tire at 65 psig is therefore at 79.7 psia, and the label psid means a difference between two pressures rather than a reference to ambient air.
Typical automobile tires are listed at about 32 psig, and road racing bicycle tires at about 120 psig. One standard atmosphere is 14.696 psi, which gives a feel for how many multiples of sea-level air those tire pressures represent.
1 pound per square inch = 6,894.757293 pascals (approximately).
Sources: Wikipedia: Pounds per square inch; Wikipedia: Standard atmosphere (unit)
Related conversions
- PSI to standard atmospheres (reverse)
- Standard atmospheres to pascals
- Standard atmospheres to kilopascals
- Standard atmospheres to bars
- Standard atmospheres to hectopascals
- Standard atmospheres to megapascals
- Standard atmospheres to millibars
- Standard atmospheres to torr
- Standard atmospheres to millimeters of mercury
- Standard atmospheres to inches of mercury
- Standard atmospheres to gigapascals
- Standard atmospheres to kilopounds per square inch
- Standard atmospheres to millimeters of water
- Pascals to PSI
- Kilopascals to PSI
- Bars to PSI
- Hectopascals to PSI
- Megapascals to PSI
- Millibars to PSI
- Torr to PSI
- Millimeters of mercury to PSI
- Inches of mercury to PSI
- Gigapascals to PSI
- Kilopounds per square inch to PSI
- Millimeters of water to PSI
See all pressure units.