Hi,
In regarding of the issue, please provide us more information to assist you better.
- Which Office version are you using? Excel 2013 or other?
- How did you export the Excel sheet as PDF? Used Acrobat Add-in for Excel or build-in feature(save as)?
Scenario One
If you used the Acrobat Add-in for Excel and then clicking on Create PDF, please try the methods below:
- In Excel, go to File > Options > Advanced> Under General section, uncheck Scale content for A4 or 8.5 x 11 paper size >click OK.
- Open the Excel file you want to convert to PDF, go to File > Save as.
- Change which printer was associated with the file
http://answers.microsoft.com/en-us/office/forum/office_2010-outlook/excel-2010-to-adobe-pdf-page-size-issue/d15d0bef-dd11-4eca-96e4-30bfd8edbdcc
Scenario Two
When using Excel if the page break size is altered to modify the print area, on exporting the Spreadsheet to PDF, the resulting page size may differ than what is set in the original document.
Cause:The problem is that when a PostScript printer is selected as the default printer for Excel, the application does not scale the sheet size. This behavior is because with PostScript the output device does the scaling rather than Excel.
To workaround this behavior, choose a PCL type printer as the default prior to exporting the document
http://support.microsoft.com/kb/2519799
Hope it's helpful.
Regards,
George Zhao
TechNet Community Support