Convert PSI to Atmospheres (atm) — Free Online Pressure Converter

Switch between PSI and atmospheres in seconds with our free online tool — built for dive planning off Vancouver Island, hyperbaric unit logs, and winter tire checks. Accurate psi to atm results.

Canadian Pressure Converter: kPa, PSI & Bar
1 psi = 0.0680459906 atm

The quick answer for 1 PSI — type any value below for the exact result

psi

PSI

atm

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. Since Canadian labels favour kilopascals, it helps to remember that 1 atm is also about 101.3 kPa.

1 psi = 0.0680459906 atm

PSI and Atmosphere Explained

PSI (psi)

PSI (pound-force per square inch) is an imperial pressure unit: one pound of force bearing on one square inch. It equals 6,894.76 pascals, or 0.068046 of a standard atmosphere. Even though Canadian tire placards list kilopascals first — check any door jamb: 220 kPa (32 PSI) — PSI is what most drivers, farmers, and divers actually read on the gauge: sea-level air shows 14.7 PSI, passenger tires 32-35 PSI, and scuba cylinders 3,000 PSI. Readings labelled PSIG measure above the surrounding atmosphere rather than including it.

Where it is used: PSI is the working pressure unit in Canada for tire gauges, air compressors, dive-shop fills, HVAC, and much industrial equipment — much of it imported from the United States — even though official documentation pairs it with kilopascals.

Origin: The unit emerged from 19th-century British engineering, pairing the imperial pound-force with the square inch, and persists across North America as the customary gauge standard.

Atmosphere (atm)

The standard atmosphere (atm) is a fixed reference pressure of exactly 101,325 pascals, chosen to represent average sea-level air. It converts gauge readings into earth-scale statements: a 44 PSI truck tire holds nearly 3 atm, an airliner cabin about 0.74 atm at cruise, and a 3,000 PSI scuba charge about 204 atm — numbers that match the depth and treatment tables used from coast to coast to coast. Diving, altitude physiology, and hyperbaric medicine lean on it because their tables are written in whole atmospheres.

Where it is used: Atmospheres anchor scuba training tables, hyperbaric therapy protocols, aviation cabin 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 11 psi 0.7485058969 atm
A hyperbaric session 37 psi 2.5177016531 atm
A mountain-bike tire at Whistler 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 up a 3,000 PSI fill at Tobermory or on a Vancouver Island charter confirm the tank holds 204.1 atm absolute, then track depth in whole atmospheres, one added per 10 metres.

Hyperbaric Oxygen Therapy

A hospital hyperbaric unit — Toronto General and Vancouver General both run chambers — logs 36.7 PSI inside; converting gives 2.5 atm, the standard wound-treatment pressure for the session record.

Aircraft Cabin Checks

Maintenance crews at YYZ or YVR log 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 CSA certification file records the equivalent 6.8 atm figure for the submission.

How to Use

  1. 1

    Enter PSI Value

    Type the PSI reading — typical entries include a cold-morning tire check (28-32 PSI), a dive tank filled at the shop (3,000 PSI), and floatplane cabin readings (10-12 PSI)

  2. 2

    View Atmosphere Result

    The atm equivalent appears instantly. For example, 32 PSI — a common Canadian tire pressure — converts to about 2.18 atm

  3. 3

    Copy or Swap

    Copy the result or click Swap to convert atmospheres back to PSI

  4. 4

    Check Gauge vs Absolute

    Remember that most gauges read PSIG (above ambient air), even though Canadian tire placards list kPa alongside PSI. Add 14.7 PSI — one more atmosphere — before comparing to absolute-pressure figures

Why Use Be Converter?

Instant Conversion

Get precise PSI to atm results in real-time as you type — perfect for Tobermory dive charters and hospital chamber logs

High Accuracy

Uses 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 common values like 14.7 PSI (1.0 atm), 32 PSI (2.18 atm), and 3,000 PSI (204.1 atm)

Bidirectional

Easily swap between PSI and atmospheres with one click for reverse conversions

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Frequently Asked Questions

How many atmospheres is 1 PSI?
1 PSI equals 0.068046 atm. In reverse, 1 atm = 14.695943 PSI — which is why sea-level air pressure shows about 14.7 PSI on a gauge that is open to the atmosphere, from Halifax Harbour to the BC coast.
What is 14.7 PSI in atm?
14.7 PSI × 0.068046 = 1.0003 atm — effectively standard sea-level pressure. The 0.03 percent gap exists only because 14.7 is a rounded version of 14.695943 PSI.
What is the difference between PSI and atm?
PSI is the imperial unit still printed on most North American gauges, while the standard atmosphere is a fixed reference equal to average sea-level air pressure (101,325 Pa — about 101.3 kPa on Canadian labels). PSI measures any pressure on a fine scale; atm tells you how many "layers of sea-level air" a pressure equals, which is why diving and altitude work favour it.
How do I convert scuba tank pressure from PSI to atm?
Multiply PSI by 0.068046. A standard 3,000 PSI aluminum tank — the workhorse at most Canadian dive shops — holds 204.1 atm, a 32 PSI passenger tire sits at 2.18 atm, and a 44 PSI light-truck tire reaches almost exactly 3 atm (2.99).
Do I add atmospheric pressure when converting?
If your gauge reads PSIG (most do), add 14.7 PSI before converting to absolute atmospheres: 30 PSIG + 14.7 = 44.7 PSIA = 3.04 atm. Gauges marked PSIA already include ambient air, so convert directly.
How many atmospheres is 40 PSI?
40 × 0.068046 = 2.72 atm if the reading is absolute. If 40 PSI is a gauge value and you need absolute pressure, add one more atmosphere for a total of 3.72 atm.
How deep underwater is 3 atm?
About 20 metres (66 feet) in seawater. Pressure rises roughly 1 atm per 10 metres of seawater, so 44 PSI — which converts to 2.99 atm — marks the absolute pressure at the standard 20 m training depth. In freshwater, like the dive sites at Fathom Five National Marine Park in Tobermory, 3 atm sits about half a metre deeper.
What is 2000 PSI in atm?
2,000 PSI × 0.068046 = 136.1 atm. That is a typical paintball or high-pressure cylinder charge on an absolute scale, well beyond any breathing-gas scuba rating.

About Our PSI to Atmosphere Converter

Our free online PSI to atmosphere converter translates imperial gauge readings into earth-scale terms for Canadian users. Whether you are planning a cold-water dive off Vancouver Island or at Fathom Five in Tobermory with a 3,000 PSI cylinder, logging a hyperbaric oxygen session at a hospital chamber, checking cabin pressurization on a regional flight, or certifying a pressure vessel under CSA rules, this tool delivers the exact equivalent. Canadian labels favour metric kilopascals — but the gauges in most garages, dive shops, and on equipment imported from the United States still show PSI, while the standard atmosphere — fixed at 101,325 Pa — anchors diving tables, altitude physiology, and hyperbaric medicine. Our converter applies the exact factor where 1 PSI equals 0.068046 atm.

Expert Tips for PSI to Atmosphere Conversion

1

Anchor points worth memorizing: 14.7 PSI ≈ 1 atm (about 101.3 kPa), 30 PSI ≈ 2.04 atm, 44 PSI ≈ 2.99 atm, and 3,000 PSI ≈ 204.1 atm — sea level, a cold-morning tire, a light-truck tire, and a scuba cylinder

2

In diving, add one atmosphere per 10 metres of seawater: at 20 m you breathe about 3 atm absolute regardless of what the tank gauge says — the same tables used by charters off Vancouver Island and at Tobermory

3

Hyperbaric oxygen therapy commonly runs 2.0-2.5 atm absolute — 29.4 to 36.7 PSI (roughly 203-252 kPa) on the chamber gauge — and treatment logs at Canadian hospital units may ask for both figures

4

Aircraft cabins hold near 10.9 PSI absolute at cruise (0.74 atm), equivalent to an 8,000-foot cabin altitude — a quick check whether you fly with Air Canada, WestJet, or a northern bush operator

5

Cold weather plays tricks: a 32 PSI tire reading in the garage can drop into the high 20s during a Winnipeg January — so settle gauge-vs-absolute too, since PSIG readings omit the 14.7 PSI of ambient air while dive and medical numbers are almost always absolute