Megapascals to pounds per square inch conversion calculator above calculates how many pounds per square inch are in 'X' megapascals (where 'X' is the number of megapascals to convert to pounds per square inch). In order to convert a value from megapascals to pounds per square inch (from MPa to psi) type the number of MPa to be converted to psi and then click on the 'convert' button.