How this calculator works
The pascal is one newton per square metre. The pound per square inch uses the international avoirdupois pound and the international inch. One pound-force is 4.4482216152605 newtons, and one square inch is 0.00064516 square metres, so one psi is exactly 6894.757293168 pascals. Converting pascals to psi divides by that number; converting psi to pascals multiplies by it. Both units express the same kind of pressure, but the page does not change the reference: an absolute pressure stays absolute and a gauge pressure stays gauge. The table also shows the same pressures in kilopascals, bar and standard atmospheres.
Formula
psi = Pa / 6894.757293168. Pa = psi x 6894.757293168. 1 standard atmosphere = 101,325 Pa = 14.6959487755 psi.
Worked example
101,325 Pa is 101325 / 6894.757293168 = 14.6959487755 psi, the pressure of one standard atmosphere. In reverse, a tyre gauge reading of 32 psi is 32 x 6894.757293168 = 220,632.2334 Pa, or about 220.6 kPa.
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Frequently asked questions
Is psi gauge pressure or absolute pressure?
It can be either. A tyre gauge reads gauge pressure, measured from the surrounding atmosphere. A pressure in pascals is absolute unless the context says otherwise. This page converts the number you enter without adding or subtracting atmospheric pressure.
Why is one psi not exactly 6895 Pa?
The exact value is 6894.757293168 Pa, based on the international pound-force and square inch. Rounding to 6895 Pa is fine for most engineering estimates but shifts a high-pressure reading slightly.
Can I enter a negative pressure?
Yes. A negative value can describe a pressure difference or gauge reading below the ambient pressure. A negative absolute pressure is not physical, so interpret the sign in the same reference as your measurement.