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Atmospheres to pounds per square inch

Multiply atmospheres by 14.6959 to get pounds per square inch.

1 atm = 14.6959 psiNIST SP 811
atm
73.4797psi

5 atm = 73.4797 psi

How to convert atmospheres to pounds per square inch

The pound per square inch is pounds-force per square inch, exactly 6894.757293168 pascals. The atmosphere is the standard atmosphere, exactly 101 325 pascals.

Worked example — 5 atm: 5 × 14.6959 = 73.4797 psi.

Atmospheres to pounds per square inch table

Common conversions.
AtmospheresPounds per square inch
0.5 atm7.348 psi
1 atm14.6959 psi
2 atm29.3919 psi
3 atm44.0878 psi
5 atm73.4797 psi
10 atm146.9595 psi
20 atm293.919 psi
50 atm734.7974 psi
100 atm1,469.5949 psi

Reverse and related

About atmospheres and pounds per square inch

Atmosphere (atm)

1 atm = 14.6959 psi

Definition. The standard atmosphere, exactly 101 325 pascals

History and origin

The standard atmosphere was defined as a reference pressure of exactly 101 325 pascals, close to average pressure at sea level. It gave a convenient benchmark before the pascal became standard.

Current use

Atmospheres are used in diving, chemistry and when describing pressure at altitude.

Source: NIST SP 811, App. B; ISO 80000-4. Exact SI values are definitional (bar = 10⁵ Pa, atm = 101 325 Pa) or derived from the pound (NIST HB 44) and standard gravity 9.80665 m/s² (psi)

Pound per square inch (psi)

1 psi = 0.068046 atm

Definition. Pounds-force per square inch, exactly 6894.757293168 pascals

History and origin

The pound per square inch comes from the imperial system, expressing pressure as pounds-force spread over a square inch. It equals about 6895 pascals.

Current use

Psi is the everyday pressure unit in the United States for tyre pressure, plumbing and compressed air.

Source: NIST SP 811, App. B; ISO 80000-4. Exact SI values are definitional (bar = 10⁵ Pa, atm = 101 325 Pa) or derived from the pound (NIST HB 44) and standard gravity 9.80665 m/s² (psi)

Where people use this

Atmospheres: diving, chemistry, altitude. Pounds per square inch: tyre pressure in the US, plumbing, compressed air. 1 atm is about 14.7 psi.

How we know this is right
The factor is fixed by the standards that define the units, not chosen — so it is exact, not a measurement:
1 psi = 0.06804596391 atm, so 1 atm = 1 ÷ 0.06804596391 = 14.6959 psi.

Every value is carried to full double precision; the display is rounded.

Both units are defined in NIST SP 811, App. B; ISO 80000-4. Exact SI values are definitional (bar = 10⁵ Pa, atm = 101 325 Pa) or derived from the pound (NIST HB 44) and standard gravity 9.80665 m/s² (psi).

Questions people ask

How many psi is 1 atm?

One atmosphere is about 14.7 psi.

How many psi is 2 atm?

2 atm is about 29.4 psi.

What is standard atmospheric pressure?

One standard atmosphere is 101,325 Pa, about 14.7 psi.

All atmosphere conversions