Atmospheres to PSI
Convert atmosphere to pound/inch² instantly — type a value and read the result, with the exact formula shown.
Example
1 atm = 14.69595 psi, 5 atm = 73.47974 psi, 10 atm = 146.9595 psi.
How it works
Pound/inch² = Atmosphere × 14.69595. Every value is converted through a single pascal base unit using internationally defined conversion factors, so any from/to pair stays consistent.
Good to know
Converting standard atmospheres to PSI is a daily task for anyone who works between scientific and American engineering contexts: a chemist reading a reaction vessel rated in atm, a scuba diver translating depth pressure into the PSI markings on a tank gauge, or a tire and HVAC technician double-checking a spec sheet that quotes pressure the "metric" way. The atmosphere is a reference unit based on average sea-level air pressure, while PSI is the imperial workhorse stamped on gauges across the United States, so moving between them is really about bridging two measurement cultures rather than two physics.
The standard atmosphere was originally defined as the pressure of Earth's air at sea level and is now fixed at exactly 101,325 pascals; PSI comes from pounds-force pressing on a square inch and equals about 6,895 pascals. Divide one by the other and you get the conversion: 1 atm equals roughly 14.696 PSI. A useful rule of thumb is that one atmosphere is "just under 15 PSI" — so to estimate quickly, multiply your atm figure by 15 and shave off about 2 percent. For example, 3 atm is close to 45 PSI (44.09 exactly), and 6 atm lands near 90 PSI (88.18 exactly).
The most common mistake is confusing the atmosphere (atm) with the technical atmosphere (at), bar, or "atmospheres absolute" used in diving. The bar is very close to atm but not identical — 1 bar is about 14.504 PSI versus 14.696 for atm — so swapping them introduces a small but real error. Likewise, gauge PSI (PSIG) measures pressure above the surrounding air, whereas the atmosphere is an absolute unit, so a tire reading "32 PSI" on a gauge is actually about 46.7 PSI absolute, or roughly 3.18 atm, once you add the atmosphere you're already breathing.
Frequently asked questions
How do you convert atmosphere to pound/inch²?
Multiply the number of atmospheres by 14.69595 to get pound/inch²s. For example, 1 atm = 14.69595 psi.
What is 1 atmosphere in pound/inch²s?
1 atmosphere equals 14.69595 pound/inch²s (1 atm = 14.69595 psi).
How many atmospheres are in 1 pound/inch²?
There are 0.06804596 atmospheres in 1 pound/inch².
Is this converter free and private?
Yes. It runs entirely in your browser, so your inputs never leave your device, there is no sign-up, and it works offline once loaded.
Are the conversions exact?
Conversions use internationally defined factors and are exact where the definitions are exact (for example, 1 inch = 2.54 cm). Displayed results are rounded for readability.
People also ask
How many PSI is 2 atmospheres of pressure?
2 atmospheres equals 29.3919 PSI (2 × 14.69595). A quick mental estimate is just under 30 PSI.
Why is 1 atm equal to 14.7 PSI and not exactly 15?
Because the standard atmosphere is defined as exactly 101,325 pascals, and one PSI is about 6,894.76 pascals. Dividing those gives 14.69595 PSI, slightly less than 15.
Is atmospheric pressure 14.7 PSI absolute or gauge?
It is 14.7 PSI absolute (PSIA). At normal sea level a gauge that reads zero (0 PSIG) is actually sitting at about 14.7 PSIA because gauges measure pressure relative to the surrounding air.
What is the difference between atm and bar when converting to PSI?
They are close but not equal: 1 atm = 14.69595 PSI while 1 bar = 14.50377 PSI. The atmosphere is defined as 101,325 Pa and the bar as exactly 100,000 Pa, so atm is about 1.3 percent higher.
How do I convert PSI back to atmospheres?
Divide the PSI value by 14.69595, or multiply by 0.06804596. For example, 30 PSI is about 2.04 atm.
How many atmospheres is 100 PSI?
100 PSI is about 6.8046 atmospheres (100 × 0.06804596). Roughly speaking, every 14.7 PSI adds one atmosphere.
What pressure in PSI does a scuba diver feel at 10 meters underwater?
At 10 meters of seawater the absolute pressure is about 2 atm, which equals roughly 29.4 PSI absolute. Every additional 10 meters of depth adds about one more atmosphere, or another 14.7 PSI.
Is 1 atm the same as the technical atmosphere (at)?
No. The standard atmosphere (atm) is 101,325 Pa and equals 14.69595 PSI, while the technical atmosphere (at) is 98,066.5 Pa and equals about 14.2233 PSI.
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