Creating a summary worksheet to show the totals from several other spreadsheets is a snap using dynamic links in Excel. If a total on one spreadsheet changes, Excel automatically updates the number on the summary sheet. Not only can you link to worksheets in the same file, you can link to worksheets in other files. Excel automatically checks the other files for changes while your summary sheet is open. Warnings Writer Bio

How to Forward Totals From One Spreadsheet to a Total Spreadsheet for Microsoft Excel - 19