Megapascal is a multiple unit of Pascal (1 MPa = 1,000,000,000 Pa). The Pascal is an SI unit of pressure measurement. It is more commonly used in many countries. It is named after the French mathematician, inventor and physicist Blaise Pascal. The Pascal being a measure of force per unit area is defined as one Newton per square metre. 
1 Pa = 1 N / 1 m2

Megapascal (MPa)

In the base units of SI, one Pascal can be expressed as

1 Pa = 1 kg / 1 m * s2

 

The standard atmospheric pressure is 101,325 Pa or 0.101325 MPa.

As with ksi, megapascal is also widely used in materials science to measure the tensile strength and the stiffness of materials. 

The other common multiple units of the Pascal are

·The hectopascal (1 hPa = 100 Pa)

·The kilopascal (1 kPa = 1000 Pa )

·The gigapascal (1 GPa = 1,000,000,000 Pa)

 

The megapascal being an SI unit has largely replaced ksi in most countries as the measurement unit of pressure except in the few countries that still use the Imperial measurement system.

Learn more about Megapascal (MPa) here