Select the cells, rows, or columns you want to expand
Drag the row boundary downward to increase row height
Drag the column boundary to the right to increase column width
Double-click the row or column boundary to auto-fit the content
Use the Home tab
Click Format in the Cells group
Choose Row Height or Column Width
Enter the desired size and click OK
Select multiple rows or columns before resizing to expand them together
Use AutoFit Row Height or AutoFit Column Width from the Format menu
Press Alt, H, O, I to auto-fit column width
Press Alt, H, O, A to auto-fit row height
Use the mouse wheel with Ctrl held down to zoom the sheet if needed
Merge adjacent cells if you want a larger single cell area
Increase font size or wrap text to make cell content fit better