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.

The standard atmosphere (atm) is a pressure unit defined as exactly 101,325 pascals, representing the average atmospheric pressure at sea level on Earth. It serves as a reference point in chemistry for gas law calculations and in engineering for rating pressure vessel capacities. One atmosphere equals approximately 1.01325 bar, 14.696 psi, or 760 mmHg.