Adding Data Labels To An Excel Chart - MyExcelOnline In our example below, I add a Data Label to a column chart and then I format the data label using CTRL+1. I then select to custom format the numbers so it shows the values as thousands by adding a comma , after each zero and then showing the work k by adding "k" Example Custom Number Format: [$$-1004]#,##0 ,"k" ;- [$$-1004]#,##0 ,"k"