My scuba tank is rated for 3,000 psi. How many atmospheres is that?

3,000 ÷ 14.696 ≈ 204 atm. Scuba tanks hold air at very high pressure.

Is 1 atm the same as 1 bar?

Close but not exact: 1 atm = 1.01325 bar. The bar is defined as 100,000 Pa. The atmosphere is defined as 101,325 Pa.

What's the pressure at 10 meters underwater?

Approximately 2 atm (1 atm air + ~1 atm water). About 29.4 psi.

Atmospheres (atm) to PSI Converter

Enter a value to instantly convert between pressure units.

From

Precision4 dp

1 Atmosphere = 14.6959 Pound per Sq. Inch

Key Formulas

Pound per Sq. Inch → Bar

bar = psi × 0.0689476

Bar → Pound per Sq. Inch

psi = bar × 14.5038

Atmosphere → Pound per Sq. Inch

psi = atm × 14.6959

Pound per Sq. Inch → Atmosphere

atm = psi × 0.068046

Formula

psi = atm × 14.6959

Atmospheres (atm) measure pressure in multiples of sea-level air pressure. PSI is the pound-force per square inch, an inch-pound unit. One atmosphere equals roughly 14.7 psi, about the air pressure that ordinary gauges treat as zero. This conversion is useful in chemistry, physics, and diving.

Source: NIST SP 811, Table B.8

Reviewed by the Convert Calc editorial team · Last reviewed: 2026-10-06 · see our methodology

Frequently Asked Questions

Real-World Examples

Atmospheric pressure at sea level. 1 atm = 14.696 psi absolute; a gauge open to the air reads 0.

1 atm = 14.696 psi

Double atmosphere. At about 10 m (33 ft) under water, the total pressure is about 2 atm.

2 atm = 29.4 psi

Ten atmospheres. 10 atm is about 147 psi.

10 atm = 146.96 psi

Half atmosphere. Low vacuum or partial pressure. ~7.35 psi.

0.5 atm = 7.35 psi

psi to bar bar to psi psi to atm kpa to psi psi to kpa

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