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