Understanding Number Formats

In Excel number formats tell your spreadsheet what data you're using. Use custom number formatting in Excel to improve spreadsheets.

Number formatting tips

Here are a few tips for getting the best results with number formatting:

Increase and Decrease Decimal

The Increase Decimal and Decrease Decimal commands allow you to control how many decimal places are displayed in a cell. These commands don't change the value of the cell; instead, they display the value to a set number of decimal places.

The Increase and Decrease Decimal commands

Decreasing the decimal will display the value rounded to that decimal place, but the actual value in the cell will still be displayed in the formula bar.

The number may display rounded

The Increase/Decrease Decimal commands don't work with some number formats, like Date and Fraction.


  1. Open our practice workbook.
  2. In cell D2, type today's date and press Enter.
  3. Click cell D2 and verify that it is using a Date number format. Try changing it to a different date format (for example, Long Date).
  4. In cell D2, use the Format Cells dialog box to choose the 14-Mar-12 date format.
  5. Change the sales tax rate in cell D8 to the Percentage format.
  6. Apply the Currency format to all of column B.
  7. In cell D8, use the Increase Decimal or Decrease Decimal command to change the number of decimal places to one. It should now display 7.5%.
  8. When you're finished, your spreadsheet should look like this:
    Number Formats Challenge