How many megapascals are in 1 psi?

1 psi equals 0.0068947573 megapascals, using the exact defined conversion factor rather than an estimate.

How do I convert psi to megapascal?

Multiply the psi value by 0.006894757293. The converter above does this instantly to whatever precision you set.

How do I convert megapascal back to psi?

Use the reverse factor: 1 megapascal equals 145.0377377 psi. You can also use the swap control in the converter above to flip the direction instantly.

What is a megapascal?

Megapascal (MPa) is a unit of pressure.

Is the psi to megapascal conversion exact?

Yes. PSI (pounds-force per square inch) equals exactly 6,894.757293168 pascals. That fixed definition is what the converter above uses, so any rounding you see is a display choice, not a limitation of the math.

PSI to Megapascals Converter

Q: What is a psi?

PSI (psi) measures pressure. PSI (pounds-force per square inch) equals exactly 6,894.757293168 pascals. It is classified as a US/imperial customary unit.

About Converting PSI to Megapascals

PSI and Megapascal both show up on pressure gauges — psi is standard on US tire and tool specifications, while bar is the everyday pressure unit across most of the rest of the world. PSI is most often used for tire pressure specifications in the us.

Formula

megapascals = psi × 0.00689475729317

This factor comes from each unit's defined relationship to the category's base unit: 1 psi equals 6894.75729317 base units, and 1 megapascal equals 1000000 base units, so dividing one by the other gives the direct psi-to-megapascal factor of 0.00689475729317.

Simple example

1 psi × 0.006894757293 = 0.0068947573 MPa

1 psi = 0.0068947573 megapascals.

Real-world example

35 psi × 0.006894757293 = 0.2413165053 MPa

35 psi = 0.2413165053 megapascals.

Conversion table

PSI (psi)	Megapascal (MPa)
1 psi	0.0068947573 MPa
5 psi	0.0344737865 MPa
10 psi	0.0689475729 MPa
25 psi	0.1723689323 MPa
50 psi	0.3447378647 MPa
100 psi	0.6894757293 MPa

Reverse conversion: Megapascal to PSI

0.0068947573 MPa × 145.0377377 = 1.000000001 psi

0.0068947573 megapascals = 1.000000001 psi.

psi = megapascals × 145.03773773

For a page dedicated to this direction, see Megapascal to PSI.

Understanding the PSI

PSI (psi) measures pressure. PSI (pounds-force per square inch) equals exactly 6,894.757293168 pascals. It is classified as a US/imperial customary unit.

Where it's used: United States (standard pressure unit for tires, tools, and plumbing)

Uses of the PSI today

Tire pressure specifications in the US
Hydraulic and pneumatic system ratings
Plumbing, compressed-air tools, and industrial equipment ratings

History of the PSI

PSI is a derived unit from the pound-force and the inch, both themselves standardized through English and later international agreements rather than invented as a pressure unit from scratch.

It became the default pressure unit in US engineering as pound-force and inch-based measurement dominated American industry through the 19th and 20th centuries, and it remains in everyday use for tires and tools even as most other measurements in the US context stay imperial.

Historical origin. PSI was not the invention of a single named person; it developed through the process described above.

Understanding the Megapascal (MPa)

Megapascal is 1000000 pascal units.

PSI — sources

NIST Special Publication 811 — Guide for the Use of the International System of Units — Documents conversion factors for psi and other US customary pressure units.

PSI to Megapascals Converter — psi to MPa

Pressure Converter