PSI to atm Calculator – Free Online Pressure Conversion
Turn any PSI gauge reading into atmospheres instantly with our free calculator — built for US scuba divers, pilots, wound-care techs, and engineers. Accurate psi-to-atm results, no signup.
US Standard Pressure Converter & CalculatorThe quick answer for 1 PSI — type any value below for the exact result
PSI
Atmosphere
PSI to Atmosphere Conversion Formula
To convert PSI to atmospheres, multiply the PSI value by 0.068046. One standard atmosphere equals 101,325 Pa, and one PSI equals 6,894.76 Pa, so it takes 14.695943 PSI to make 1 atm.
PSI and Atmosphere Explained
PSI (psi)
PSI (pound-force per square inch) is the American pressure unit: one pound of force pressing on one square inch. It equals 6,894.76 pascals, or 0.068046 of a standard atmosphere. The scale matches US hardware naturally — sea-level air reads 14.7 PSI, sedan tires run 32–35 PSI, and scuba cylinders hold 3,000 PSI — and readings labeled PSIG measure above the surrounding atmosphere rather than including it.
Where it is used: PSI is the default pressure unit across the United States — tires, air compressors, domestically sold dive cylinders, plumbing, HVAC, and industrial equipment.
Origin: The unit grew out of 19th-century British engineering, pairing the pound-force with the square inch, and survives today as a US customary standard stamped on American gauges.
Atmosphere (atm)
The standard atmosphere (atm) is a fixed reference pressure of exactly 101,325 pascals, chosen to represent average sea-level air. It turns gauge readings into earth-scale statements: a 44 PSI pickup tire holds nearly 3 atm, an airliner cabin about 0.74 atm at cruise, and a 3,000 PSI scuba fill about 204 atm. Diving, altitude physiology, and hyperbaric medicine rely on it because depth and treatment tables are written in whole atmospheres.
Where it is used: Atmospheres anchor scuba training tables, hyperbaric therapy protocols, FAA cabin pressurization standards, and chemistry reference conditions.
Origin: Nineteenth-century metrologists sought a "normal" air pressure for gas measurements; the value was ultimately fixed at exactly 101,325 Pa by international agreement in the 1950s.
PSI to Atmosphere Conversion Table
| PSI (psi) | Atmosphere (atm) |
|---|---|
| 1 psi | 0.0680459906 atm |
| 2 psi | 0.1360919812 atm |
| 5 psi | 0.3402299531 atm |
| 10 psi | 0.6804599062 atm |
| 11 psi | 0.7485058969 atm |
| 14.5 psi | 0.9866668641 atm |
| 14.7 psi | 1.0002760622 atm |
| 15 psi | 1.0206898594 atm |
| 20 psi | 1.3609198125 atm |
| 25 psi | 1.7011497656 atm |
| 30 psi | 2.0413797187 atm |
| 40 psi | 2.721839625 atm |
| 50 psi | 3.4022995312 atm |
| 60 psi | 4.0827594375 atm |
| 80 psi | 5.4436792499 atm |
| 100 psi | 6.8045990624 atm |
| 150 psi | 10.2068985936 atm |
| 200 psi | 13.6091981248 atm |
Atmosphere to PSI Conversion Table
| Atmosphere (atm) | PSI (psi) |
|---|---|
| 0.1 atm | 1.4695943006 psi |
| 0.25 atm | 3.6739857515 psi |
| 0.33 atm | 4.849661192 psi |
| 0.5 atm | 7.347971503 psi |
| 0.75 atm | 11.0219572545 psi |
| 1 atm | 14.695943006 psi |
| 1.5 atm | 22.043914509 psi |
| 2 atm | 29.391886012 psi |
| 2.5 atm | 36.739857515 psi |
| 3 atm | 44.087829018 psi |
| 5 atm | 73.47971503 psi |
| 10 atm | 146.9594300599 psi |
| 20 atm | 293.9188601199 psi |
PSI to Atmosphere in Everyday Objects
Common real-world examples that make PSI and Atmosphere easy to picture at a glance.
| PSI (psi) | Atmosphere (atm) | |
|---|---|---|
| Sea-level air pressure | 14.7 psi | 1.0002760622 atm |
| A full scuba cylinder | 3000 psi | 204.1379718727 atm |
| An airliner cabin at cruise | 11 psi | 0.7485058969 atm |
| A hyperbaric session | 37 psi | 2.5177016531 atm |
| A mountain bike tire | 30 psi | 2.0413797187 atm |
| A paintball cylinder charge | 4500 psi | 306.206957809 atm |
When You Need PSI to Atmosphere Conversions
Scuba Dive Planning
Divers topping off 3,000 PSI fills before the boat leaves the dock in Key Largo — 204.1 atm absolute — then track depth in whole atmospheres, one added per 33 feet.
Hyperbaric Oxygen Therapy
A wound-care center in Houston logs 36.7 PSI inside the hyperbaric chamber; converting gives 2.5 atm, the standard treatment pressure for the session record.
Aircraft Cabin Checks
A technician at Denver International logs a cabin pressure of 10.9 PSI at cruise altitude — 0.74 atm, matching the 8,000-foot equivalent cabin standard.
Pressure-Vessel Certification
A hydrostatic test presses a vessel to 100 PSI, and the certification sheet for the SI archive needs 6.8 atm as the recorded figure.
Related Pressure Conversions
How to Use
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1
Enter PSI Value
Type the gauge reading — typical entries include sea-level air (14.7 PSI), a 3,000 PSI scuba tank filled in Key Largo, or an airliner cabin at cruise (~11 PSI)
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2
View Atmosphere Result
The atm equivalent appears instantly. For example, 30 PSI — a typical sedan tire on an American highway — converts to about 2.04 atm
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3
Copy or Swap
Copy the result or hit Swap to convert atmospheres back to PSI
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4
Check Gauge vs Absolute
Remember that most US gauges read PSIG (above ambient air). Add 14.7 PSI — one more atmosphere — before comparing against absolute-pressure figures
Why Use Be Converter?
Instant Conversion
Results update in real time as you type — handy for filling out dive logs after a Key Largo charter or recording a hyperbaric session at the wound-care center
High Accuracy
Built on the exact international standard: 1 atm = 101,325 Pa and 1 PSI = 6,894.76 Pa, accurate to 6 decimal places
Conversion Table
Quick reference with the values American technicians see daily: 14.7 PSI (1.0 atm), 44 PSI (2.99 atm), and 3,000 PSI (204.1 atm)
Bidirectional
Swap between PSI and atmospheres with a single click for fast reverse conversions
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Frequently Asked Questions
How many atmospheres is 1 PSI?
What is 14.7 PSI in atm?
What is the difference between PSI and atm?
How do I convert scuba tank pressure from PSI to atm?
Do I add atmospheric pressure when converting?
How many atmospheres is 40 PSI?
How deep underwater is 3 atm?
What is 2000 PSI in atm?
About PSI to Atmosphere Converter
Our free PSI-to-atmosphere calculator translates American gauge readings into earth-scale terms. Whether you're checking a 3,000 PSI fill on a dive boat out of Key Largo, documenting a hyperbaric chamber session at a Houston wound-care center, verifying cabin pressurization on a red-eye out of Denver, or logging a pressure-vessel hydro test for an engineering file, this tool delivers the exact atm equivalent. PSI rules US equipment panels, while the standard atmosphere — fixed at exactly 101,325 Pa — anchors dive tables, altitude physiology, and hyperbaric medicine. Our converter applies the exact factor: 1 PSI equals 0.068046 atm.
Expert Tips for PSI to Atmosphere Conversion
Anchor points worth memorizing: 14.7 PSI ≈ 1 atm, 30 PSI ≈ 2.04 atm, 44 PSI ≈ 2.99 atm, and 3,000 PSI ≈ 204.1 atm — sea level, sedan tire, pickup tire, and the aluminum 80 in your dive bag
In US diving, add one atmosphere for every 33 feet of seawater: at 66 feet you're breathing about 3 atm absolute, no matter what the tank gauge says
Hyperbaric oxygen therapy typically runs 2.0–2.5 atm absolute — 29.4 to 36.7 PSI on the clinic gauge — and US treatment logs often require both figures
US airliners pressurize cabins to roughly 10.9 PSI absolute at cruise (0.74 atm) — like sitting outdoors in Denver at 8,000 feet — a quick check for pressurization diagnostics
Always settle gauge-vs-absolute before converting: PSIG readings leave out the 14.7 PSI of ambient air, and dive, aviation, and medical numbers are almost always absolute