Use the REPT Function to Add Leading Zeros To add zeros in front of numbers in Excel is using the Repeat or REPT function. REPT function repeats the character you want a certain number of times. The REPT function requires two items: the text you want to repeat the number of times you want to repeat it So you can use a 0 as the text to repeat, followed by the number of times you would like it to appear. For example, to create a list where all cells begin with two zeros, you can use REPT to combine the number of zeros you need with the contents of the cells. It would look something like this: =REPT(0,2)&A2 Another method is by using custom formatting. For example, you can format the cells to display a set quantity of zeros in front. Let’s say you want to format your cells to display six numbers. To do this: Select all the cells you need to add a zero to, right-click and select Format Cells In the Number tab, select Custom Under Type, enter 6 zeros Click OK