Change the size of a PDF page using Acrobat DC Preflight tool on Mac

Open the PDF file with Acrobat DC on Mac.

Go to Tools > Print Production.

Select Preflight from the right pane.

In the Preflight dialog box, click Select single fixups.

Now expand the heading that says "Pages".

Under pages, look for a fixup which says "Scale pages to specified size", and then click the Edit button after highlighting the fixup.

Now enter the page measurements in the Scale pages section:

• Short edge: Width
• Long edge: Height

Now click on OK

Save the file using the Save dialog box.