In 1 pounds per square inch there are 0.068046 atmospheres. Meanwhile in 1 atmospheres there are 14.695949 pounds per square inch. Keep reading to learn more about each unit of measure and how they are calculated. Or just use the Atmospheres to Pounds per square inch calculator above to convert any number.
* Values rounded to 6 decimal places for readability
To convert pounds per square inch (PSI) to atmospheres (atm), divide the PSI value by 14.69595.
Formula:
Quick example:
Use this PSI to atm conversion when you need pressure in standard atmosphere units, such as in science, weather, or lab work.
PSI stands for pounds per square inch. It measures pressure based on force in pounds applied to an area of one square inch. PSI is common in the US for tires, air tools, and gas systems.
An atmosphere, written as atm, is a standard unit of pressure. It matches average air pressure at sea level. You’ll see atm used in science, diving, and lab work.
To convert PSI to atm, divide the PSI value by 14.6959.
Formula: atm = PSI ÷ 14.6959
1 PSI = 0.068046 atm (rounded).
That means PSI is a smaller unit, so the atm value will be lower.
1 atm = 14.6959 PSI (often rounded to 14.7 PSI).
This is a common reference point for sea-level pressure.
For a quick estimate, use 14.7 PSI ≈ 1 atm.
Then divide PSI by 14.7 to get a close atm value.
Because 1 atm is defined as 101,325 pascals, which equals 14.6959 PSI. The number comes from exact unit definitions, not a guess.
30 PSI ÷ 14.6959 = 2.041 atm (rounded).
So 30 PSI is a little over 2 atmospheres.
60 PSI ÷ 14.6959 = 4.083 atm (rounded).
Doubling PSI doubles the atm value.
100 PSI ÷ 14.6959 = 6.8046 atm (rounded).
This is useful for high-pressure air and gas tanks.
Rounding depends on how you’ll use the number. For everyday pressure checks, 2 to 3 decimals is often enough. For lab work, keep more digits to avoid error.
atm is a standard pressure unit. psia means pounds per square inch absolute. Absolute pressure is measured from a perfect vacuum, not from local air pressure.
Most PSI readings in daily use are psig (gauge pressure). Gauge pressure is measured above local air pressure. If you need absolute pressure, add local atmospheric pressure (about 14.7 PSI at sea level) to a gauge reading.
The math conversion stays the same, since it’s a unit change. But real air pressure in atm can change with altitude, weather, and temperature. Sea-level assumptions won’t match high-altitude conditions.
This conversion helps when comparing pressure specs across fields. It’s common in physics, chemistry, scuba ratings, gas laws, and pressure vessel data.
Mixing psig with psia causes errors. Rounding too early can also change results. Another common mistake is multiplying instead of dividing by 14.6959.
The Calculate Box tool to convert pounds per square inch to atmospheres uses the open source script Convert.js to convert units of measurement. To use this tool, simply type a pounds per square inch value in the box and have it instantly converted to atmospheres.