What are megapascals and psi?
Megapascals (MPa)
The megapascal (MPa) is a metric unit of pressure equal to one million pascals, where one pascal is one newton of force spread over one square meter. As an SI-based unit, the megapascal is the standard way large pressures and material stresses are expressed across most of the world in science and engineering. Because one megapascal represents a substantial pressure, the unit shows up wherever high values are involved, such as the tensile strength of steel, concrete grades, hydraulic system ratings, and the pressure inside industrial equipment.
Pounds per square inch (psi)
The pound per square inch (psi) is a unit of pressure in the imperial and United States customary systems. It measures how many pounds of force press on each square inch of area. Psi dominates American engineering and consumer products, appearing on tire gauges, air compressors, hydraulic equipment, and pipeline specifications. Because so much equipment is rated in psi, converting to and from metric units is a common task whenever American and international specifications meet.
How does the calculator work?
This converter links the two pressure units in both directions. Type a value into either field and the other updates instantly. The tool remembers which field you changed last, so it always converts from the value you entered to the matching result.
The conversion rests on a single factor: one megapascal equals 145.0377 pounds per square inch. Going the other way, you divide by that same number.
Megapascals and psi conversion formulas
To convert megapascals to psi, multiply by 145.0377:
To convert psi back to megapascals, divide by the same factor:
Conversion table
The table below shows how the two pressure units relate to each other.
| Pressure unit | Megapascals (MPa) | Pounds per square inch (psi) |
|---|---|---|
| 1 Megapascal | 1 | 145.0377 |
| 1 psi | 0.0068948 | 1 |
For related conversions, see the kPa to psi converter.
Examples
The following examples reuse the same numbers as the calculator’s test fixtures.
Example 1: Convert 1 MPa to psi
Starting from one megapascal:
So 1 MPa is about 145.04 psi.
Example 2: Convert 10 MPa to psi
For a larger pressure value:
Thus 10 MPa equals about 1450.38 psi.
Example 3: Convert 100 psi to megapascals
Working in the other direction with a common hydraulic pressure:
So 100 psi is about 0.6895 MPa.
Practical applications
Pressure conversion is routine whenever imperial and metric specifications meet. Engineers comparing the rated strength of a material quoted in megapascals with a design limit expressed in psi translate between the two so the numbers line up.
In manufacturing and construction, structural materials such as steel and concrete are often specified in megapascals on international datasheets but in psi on American ones, so converting keeps stress ratings consistent across a project.
Students and technicians also rely on this conversion when a physics problem or instrument is set up in megapascals but the reference equipment, such as a hydraulic press or pressure gauge, reads in psi.
Frequently asked questions
How do I convert megapascals to psi?
Multiply the megapascal value by 145.0377. For example, 1 MPa × 145.0377 ≈ 145.04 psi.
How many psi are in one megapascal?
One megapascal equals about 145.0377 pounds per square inch.
How many megapascals are in one psi?
One pound per square inch equals about 0.0068948 megapascals.
How do I convert psi to megapascals?
Divide the psi value by 145.0377. For example, 100 psi ÷ 145.0377 ≈ 0.6895 MPa.
What is the difference between MPa and kPa?
One megapascal equals one thousand kilopascals, since both are based on the pascal; the megapascal is simply the larger unit used for higher pressures and material stresses.