Pascals to PSI (Pa to psi)

1 pascal equals 0.0001450377377 pounds per square inch (rounded).

1 pascal = 0.0001450377377 pounds per square inch

How to convert pascals to pounds per square inch

To convert pascals to pounds per square inch, multiply the number of pascals by 0.0001450377377. The factor is rounded to 10 significant digits. To go the other way, multiply pounds per square inch by 6,894.757293 (rounded).

pounds per square inch = pascals × 0.0001450377377

Example: 10 pascals = 0.001450377377 pounds per square inch.

About these units

Pascal (Pa)

Metric (SI)Current unit

The SI unit of pressure: one newton per square meter. A very small unit; atmospheric pressure is about 101,325 Pa.

Blaise Pascal never saw a pascal, because the name was adopted by the 14th CGPM in 1971 for the newton per square meter. He did, however, earn the honor. In 1647 he published experiments on the vacuum, and on 19 September 1648 his brother-in-law Florin Périer carried a mercury barometer up the Puy de Dôme near Clermont, where the column stood at about 23 inches against about 26 at the base. Pascal had reasoned that air pressure should fall with altitude, and the result confirmed it.

One pascal is a tiny pressure, so the unit is mostly met with prefixes. Standard atmospheric pressure is 101,325 Pa, a typical sea-level reading is about 1,013 hPa, and the threshold of hearing in air is taken as a reference pressure of 20 micropascals. Building airtightness tests, in contrast, are run at 50 Pa.

Pascal is also remembered for hydrostatics, where he showed that pressure depends on height difference rather than the weight of the fluid, and for the hydraulic press.

The pascal is the reference unit for pressure on this site.

Sources: Wikipedia: Pascal (unit); Wikipedia: Blaise Pascal

Pound Per Square Inch (psi)

US & ImperialCurrent unit

About 6,894.757 pascals. The common unit for tire pressure, hydraulics and gas pipelines in the US.

Unlike most pressure units, psi has no namesake: it simply spells out its own definition, one pound-force acting on one square inch, and it is based on avoirdupois units. Used mainly in the United States, it is about 6.895 kilopascals.

The letters after the unit matter. Psia is measured against a vacuum, while psig is measured against the surrounding air, so at sea level, where the atmosphere is about 14.7 psi, you add that amount to a gauge reading to get an absolute one. A bicycle tire at 65 psig is therefore at 79.7 psia, and the label psid means a difference between two pressures rather than a reference to ambient air.

Typical automobile tires are listed at about 32 psig, and road racing bicycle tires at about 120 psig. One standard atmosphere is 14.696 psi, which gives a feel for how many multiples of sea-level air those tire pressures represent.

1 pound per square inch = 6,894.757293 pascals (approximately).

Sources: Wikipedia: Pounds per square inch; Wikipedia: Standard atmosphere (unit)

Related conversions

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