Select the column or columns you want to extend
Move the cursor to the right edge of the selected column header until it becomes a double-headed arrow
Click and drag the edge to the right to increase the column width
Double-click the right edge of the column header to auto-fit the column to the longest entry
Select multiple adjacent columns and drag one edge to extend them together
Use the Home tab, then Format, then Column Width to enter a specific width
Right-click the selected column header and choose Column Width
Copy a column and paste it into adjacent columns to extend the layout
Drag the fill handle across cells if you want to extend the data in the column
Use keyboard shortcuts like Alt, H, O, W to open Column Width settings