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