Pounds per square inch

The pound per square inch or, more accurately, pound-force per square inch (symbol: lbf/in²; abbreviation: psi) is a unit of pressure or of stress based on avoirdupois units. It is the pressure resulting from a force of one pound-force applied to an area of one square inch:

${\displaystyle 1~{\text{psi}}={\frac {1~{\text{lbf}}}{(1~{\text{in}})^{2}}}\approx {\frac {4.4482~{\text{N}}}{(0.0254~{\text{m}})^{2}}}\approx 6894.757~{\text{N}}/{\text{m}}^{2}}$

Therefore, one pound per square inch is approximately 6894.757 Pa.

Now converting the psi to standard atmospheres:

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