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Convert Atmospheres to Pounds per square inch

1 standard atmosphere is 14.695949 psi. One standard atmosphere is exactly 14.6959487755 pounds per square inch.

One standard atmosphere is 14.695949 pounds per square inch. To convert atmospheres to pounds per square inch, multiply by 14.695949; to go the other way, divide by 14.695949 or multiply by 0.068045964. The factor is exact rather than rounded: it follows from NIST Special Publication 811.

Factor checked against the defining standard · How we check

Pounds per square inch
14.695949 psi
Atmospheres × 14.695949
value * 14.695948775514.696 psi

1 standard atmosphere in every pressure unit

UnitValueExact factor
pounds per square inch14.69594878 psi× 14.6959487755
bars1.01325 bar× 1.01325
pascals101,325 Pa× 101,325
kilopascals101.325 kPa× 101.325
megapascals0.101325 MPa× 0.101325
atmospheres (as entered)1 atm
torr760 Torr× 760
inches of mercury29.9212524 inHg× 29.9212524019

Factors are entered by hand from NIST Special Publication 811 rather than derived from a units library, so the ones that terminate are exact rather than rounded.

How do you convert atmospheres to pounds per square inch?

  1. 1.Take the measurement in atmospheres.
  2. 2.Multiply by 14.695949 — that is how many pounds per square inch fit in one standard atmosphere.
  3. 3.To go back the other way, divide by 14.695949, or multiply by 0.068045964.

Worked example: 25 atmospheres to pounds per square inch

Formula
atm × 14.695949 = psi
Arithmetic
25 × 14.695949 = 367.398719 psi
Answer
25 atm = 367.398719 psi

The factor is rounded for display; the figure above is computed from the full value.

Atmospheres to pounds per square inch conversion table

AtmospheresPounds per square inch
1 atm14.695949 psi
2 atm29.391898 psi
3 atm44.087846 psi
4 atm58.783795 psi
5 atm73.479744 psi
6 atm88.175693 psi
7 atm102.871641 psi
8 atm117.56759 psi
9 atm132.263539 psi
10 atm146.959488 psi
12 atm176.351385 psi
15 atm220.439232 psi
20 atm293.918976 psi
25 atm367.398719 psi
50 atm734.797439 psi
100 atm1,469.594878 psi
200 atm2,939.189755 psi
300 atm4,408.784633 psi
500 atm7,347.974388 psi
1000 atm14,695.948776 psi
2000 atm29,391.897551 psi
5000 atm73,479.743878 psi
10000 atm146,959.487755 psi

What is a standard atmosphere?

Exactly 101,325 pascals by definition, not by measurement — it was fixed as a reference, and the real pressure outside your window is never precisely it.

What is a pound per square inch?

A pound-force spread over a square inch. Exact, because both parts are: it is 4.4482216152605 newtons divided by an inch squared. Every US tyre gauge, air line and pressure washer is marked in it.

How many pounds per square inch are in a standard atmosphere?

One standard atmosphere is 14.695949 pounds per square inch. Going the other way, one pound per square inch is 0.068045964 atmospheres. Both figures come from the same defined relation rather than from a measurement, which is why they are the same today as they were in 1959.

Every pressure unit here

UnitSymbolOne of these is
Pounds per square inchpsi6894.7573 pascal
Barsbar100000 pascal
PascalsPathe base unit
KilopascalskPa1000 pascal
MegapascalsMPa1000000 pascal
Atmospheresatm101325 pascal
TorrTorr133.32237 pascal
Inches of mercuryinHg3386.389 pascal

Source: NIST Special Publication 811 — pound-force is exactly 4.4482216152605 N and the inch exactly 0.0254 m

Questions people actually ask

How many pounds per square inch are in a standard atmosphere?
14.695949. A pound-force spread over a square inch. Exact, because both parts are: it is 4.4482216152605 newtons divided by an inch squared. Every US tyre gauge, air line and pressure washer is marked in it.
How do I convert pounds per square inch back to atmospheres?
Divide by 14.695949, or multiply by 0.068045964 — they are the same operation.

Other pressure conversions

Pounds per square inch to atmospheres — the same conversion the other way.