Convert atm to psi

One atmosphere equals 14.695949 psi. To convert any number of atmospheres to psi, multiply by 14.69594878.

The converter above works in both directions and updates as you type. Below you will find the formula, a worked example and a reference table of common values.

Pressure conversions are dominated by one everyday task: inflating a tyre. The United States and the United Kingdom quote psi, most of Europe uses bar, Canada and Australia use kilopascals, and the figure on the door jamb may not match the unit on the gauge. Beyond tyres, the same conversions serve weather reporting, diving, and any engineering work where a specification and an instrument were made in different markets.

atm to psi formula

To go the other way, use atmosphere = psi ÷ 14.69594878.

About these units

The standard atmosphere is defined as exactly 101,325 pascals, the average sea-level air pressure. It is a useful reference precisely because it is close to what a person experiences.

Pounds per square inch remains the standard for tyre pressure in the US and UK, while most of the world uses bar or kilopascals.

Atmosphere is also written atmospheres. PSI is also written pounds per square inch and lb/in2.

Sources

1. 10th General Conference on Weights and Measures (1954), Resolution 4 — the standard atmosphere as exactly 101,325 pascals.
2. National Bureau of Standards, "Refinement of Values for the Yard and the Pound", Federal Register, 1 July 1959 — the international yard as exactly 0.9144 m and the avoirdupois pound as exactly 0.45359237 kg.
3. NIST Special Publication 811, Guide for the Use of the International System of Units (SI), 2008 edition — conversion factors for units outside the SI.