How this calculator works
A megapascal is one million pascals. One psi is one pound-force per square inch. From the exact pound, standard gravity of 9.80665 m/s2 and international inch, one psi is about 6894.757293168 Pa, giving about 145.03773773 psi per MPa. This is a scale conversion that keeps the same pressure reference.
Formula
psi = MPa x 1000000 / 6894.757293168; MPa = psi x 6894.757293168 / 1000000. Exact defining expression: Pa per psi = 0.45359237 x 9.80665 / 0.0254^2.
Worked example
A 0.25 MPa pressure is about 36.25943443 psi. A 100 psi pressure is about 0.6894757293 MPa.
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Frequently asked questions
Can I convert MPa gauge into psi gauge?
Yes. A scale conversion preserves gauge reference when both sides use it.
Does MPa absolute become psig by multiplying?
No. You must first subtract the ambient absolute pressure. Use the MPa to psig calculator for that step.
Is the displayed 145.03773773 factor exact?
That decimal is rounded. The exact relationship comes from the defining pound-force and square-inch expression shown in the formula.