I want to create a cell in and Excel spreadsheet that can only have Even numbers entered into it and also one just for Odd numbers. Any ideas what formula I can put into the Data Validation formula to be able to do this. Thank you.

In the cells you want to check for even set the data validation to custom, then in the formula
check odd numbers in the same way with the formula
of course adjusting the cell address, the style, and Error Alert you want in response 


Here's an alternative that uses Excel's Odd and Even functions. Assuming you are validating for even in A2 and Odd and A3. Enter these as Custom formulas in the Data Validation dialog:


