[excel] How do I reference a cell range from one worksheet to another using excel formulas?

If these worksheets reside in the same workbook, a simple solution would be to name the range, and have the formula refer to the named range. To name a range, select it, right click, and provide it with a meaningful name with Workbook scope.

For example =Sheet1!$A$1:$F$1 could be named: theNamedRange. Then your formula on Sheet2! could refer to it in your formula like this: =SUM(theNamedRange).

Incidentally, it is not clear from your question how you meant to use the range. If you put what you had in a formula (e.g., =SUM(Sheet1!A1:F1)) it will work, you simply need to insert that range argument in a formula. Excel does not resolve the range reference without a related formula because it does not know what you want to do with it.

Of the two methods, I find the named range convention is easier to work with.