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

Convert psi to atm as you type.

Canadian Pressure Converter: kPa, PSI & Bar
1 psi ≈ 0.0680459639 atm

Reference for one unit; displayed values may be rounded.

psi

PSI

Use a dot or comma for decimals, without thousands separators.

atm

Atmosphere

Display rounding does not improve the accuracy of your original measurement. Very large or very small results use scientific notation.

Method and source

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 ≈ 0.0680459639 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

Select a value to use it in the calculator.

PSI (psi) Atmosphere (atm)
0.0680459639 atm
0.1360919278 atm
0.3402298195 atm
0.6804596391 atm
0.748505603 atm
0.9866664767 atm
1.0002756695 atm
1.0206894586 atm
1.3609192782 atm
1.7011490977 atm
2.0413789173 atm
2.7218385564 atm
3.4022981955 atm
4.0827578346 atm
5.4436771128 atm
6.804596391 atm
10.2068945865 atm
13.609192782 atm

Atmosphere to PSI Conversion Table

Atmosphere (atm) PSI (psi)
0.1 atm 1.4695948776 psi
0.25 atm 3.6739871939 psi
0.33 atm 4.8496630959 psi
0.5 atm 7.3479743878 psi
0.75 atm 11.0219615816 psi
1 atm 14.6959487755 psi
1.5 atm 22.0439231633 psi
2 atm 29.391897551 psi
2.5 atm 36.7398719388 psi
3 atm 44.0878463265 psi
5 atm 73.4797438776 psi
10 atm 146.9594877551 psi
20 atm 293.9189755103 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 1.0002756695 atm
A full scuba cylinder 3000 psi 204.1378917296 atm
An airliner cabin 11 psi 0.748505603 atm
A hyperbaric session 37 psi 2.5177006647 atm
A mountain-bike tire at Whistler 30 psi 2.0413789173 atm
A paintball cylinder charge 4500 psi 306.2068375944 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

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