The megapascal (MPa) equals one million pascals and is the standard unit for high-pressure applications in structural engineering, materials testing, and hydraulic systems. Concrete strength is rated in megapascals, and steel tensile strength specifications routinely reference this unit. One megapascal equals 10 bar or approximately 145 psi, bridging metric and imperial pressure scales.

PSI (pounds per square inch) is an imperial pressure unit equal to about 6,894.76 pascals, the standard measurement for tire pressure, compressed air systems, and hydraulic equipment in the United States. Almost every American gas station air pump and pressure washer displays ratings in PSI, making it one of the most recognized pressure units worldwide. One PSI equals approximately 0.06895 bar or 6.895 kPa.