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Convert Pounds per square inch to Atmospheres

1 pound per square inch is 0.068046 atm. One pound per square inch is exactly 0.0680459639099 atmospheres.

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

Factor checked against the defining standard · How we check

Atmospheres
0.068046 atm
Pounds per square inch × 0.068045964
value * 0.06804596390990.068 atm

1 pound per square inch in every pressure unit

UnitValueExact factor
pounds per square inch (as entered)1 psi
bars0.06894757293 bar× 0.0689475729317
pascals6,894.757293 Pa× 6,894.75729317
kilopascals6.894757293 kPa× 6.89475729317
megapascals0.006894757293 MPa× 0.00689475729317
atmospheres0.06804596391 atm× 0.0680459639099
torr51.71493257 Torr× 51.7149325715
inches of mercury2.036020461 inHg× 2.03602046108

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 pounds per square inch to atmospheres?

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

Worked example: 25 pounds per square inch to atmospheres

Formula
psi × 0.068045964 = atm
Arithmetic
25 × 0.068045964 = 1.701149 atm
Answer
25 psi = 1.701149 atm

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

Pounds per square inch to atmospheres conversion table

Pounds per square inchAtmospheres
1 psi0.068046 atm
2 psi0.136092 atm
3 psi0.204138 atm
4 psi0.272184 atm
5 psi0.34023 atm
6 psi0.408276 atm
7 psi0.476322 atm
8 psi0.544368 atm
9 psi0.612414 atm
10 psi0.68046 atm
12 psi0.816552 atm
15 psi1.020689 atm
20 psi1.360919 atm
25 psi1.701149 atm
50 psi3.402298 atm
100 psi6.804596 atm
200 psi13.609193 atm
300 psi20.413789 atm
500 psi34.022982 atm
1000 psi68.045964 atm
2000 psi136.091928 atm
5000 psi340.22982 atm
10000 psi680.459639 atm

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.

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.

How many atmospheres are in a pound per square inch?

One pound per square inch is 0.068045964 atmospheres. Going the other way, one standard atmosphere is 14.695949 pounds per square inch. 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 atmospheres are in a pound per square inch?
0.068045964. 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.
How do I convert atmospheres back to pounds per square inch?
Divide by 0.068045964, or multiply by 14.695949 — they are the same operation.

Other pressure conversions

Atmospheres to pounds per square inch — the same conversion the other way.