The custom format feature in Excel allows the user to “paint” or mask a number, text, date or time value in a user defined custom format. Before we get into the details, it is important to remember that when you format a cell using this feature, it does not change the value present in the cell. The only change is of how the value appears to the user on the screen.
A custom format can be applied to a particular cell or a group of cell. Using this feature will retain the underlying data but will change its appearance on the screen. For example, suppose you have a figure, say 100, present in a particular cell of a column which stores the daily sales for a product. Now if you wanted to change the appearance of this cell and convert this to $’s (without actually changing the actual value), you can use the custom format feature so that the number is shown as $ 100 and not 100. The actual value in the cell remains 100. Similarly you can also change this cell to appear as “You scored 100” while the actual value remains 100. So as you can see, the custom format feature can help make cell values more descriptive and help the reader make better sense of the data. Let’s move on.