For an Excel formula that needs to reference a cell in a different worksheet in the same workbook, use the following format for your formula.
SheetName!CellAddress (Precede the cell address with the worksheet name, and follow it with an exclamation point).
Note: For worksheet names that include one or more spaces, you will need to enclose it in single quotation marks. The following is a formula that refers to a cell on a sheet by the name of Monthly Sales:
=B4*’Monthly Sales’!A12
