As a persistent setting for the worksheet, go to the Page Layout tab then click the Size button in the Page Setup group & select the size you want, Be sure to save changes to the file. For the current job only, go to File> Print, then choose from the Paper Size drop down menu.
In this way, how do I convert Excel A3 to PDF?
In order to set the Paper Size to A3, go to the File menu – Print – Page Setup and from “Page” tab, “Paper Size” field, select A3 and press “OK” in order for changes to take effect. After that, go to the File menu – Export and select the “Export to PDF” option.
Also to know is, how do I format an Excel spreadsheet for printing?