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Atmospheres to PSI Converter

↔ Convert psi to atm instead

Common Conversions

atm psi
0.1 1.47
0.5 7.348
1 14.696
2 29.392
5 73.48
10 146.96
20 293.92
50 734.8
100 1469.6
150 2204.4
200 2939.2

Why this conversion matters in chemistry

Of all the pressure units a chemist runs into, psi is the only one defined directly through force per unit area — pounds of force on a square inch of gauge face — rather than through a fluid column or a coherent SI definition. A fresh nitrogen cylinder delivered at about 150 atm reads something like 2200 psi on the regulator, which is worth knowing when sizing a gas manifold or estimating how long a cylinder will last at a given flow. High-pressure hydrogenations and supercritical-fluid work routinely run at hundreds of atm, where the psi number on the gauge starts looking large and the conversion to atm becomes the thing that keeps a PV = nRT calculation honest.

Formula

psi = atm × 14.696

Worked Examples

1 atm = 14.696 psi

Standard atmospheric pressure — the baseline on any sea-level pressure gauge.

150 atm = 2204.4 psi

The typical delivered pressure of a full compressed-gas cylinder of nitrogen or argon.

0.5 atm = 7.348 psi

A modest vacuum, still within reach of a water aspirator at the tap.

200 atm = 2939.2 psi

The kind of pressure a sealed hydrogenation reactor runs at for a high-pressure reduction.

Frequently Asked Questions

How many psi are in 1 atm?
14.696 psi, often rounded to 14.7 for rough calculations. That's the pressure the atmosphere exerts on every square inch of everything at sea level.
When do chemists actually encounter psi?
Compressed-gas cylinder regulators and flow controllers in US labs, autoclave pressure gauges, some HPLC back-pressure readouts, and anything built to US industrial specs. For a gas-law calculation, the psi reading usually has to come back to atm or kPa first.
What's the difference between psi and psig?
Psi (or psia) is absolute pressure, measured against a perfect vacuum. Psig is gauge pressure, measured against the atmosphere outside the gauge. At sea level, psig = psia − 14.696. A tire gauge reading 32 psig is really 46.7 psia inside the tire.