# 22. Excel How to calculate a percentage?

The ratio of a part to a whole is the ratio of the value of the part to the value of the whole.

For example, 17 passes out of 20 students. The pass rate is 17/20 = 0.85.

To express a rate in percent, multiply by 100 and put a % sign in front of it.

The pass percentage for the above example is: 17/20 x 100 = 85%.

In Excel, it is recommended that you only write the ratio and then use the **Percent Style** button in the **Number** group on the **Home** tab.

In the following example,

I wrote in cell B6 the formula :

=B3/B5

That is

=17/20

To get the percentage value, I then click on the **Percent Style** button in the **Number** group on the **Home** tab.

You can also increase or decrease the number of digits after the decimal point by using the **Increase Decimal** Button or the **Decrease Decimal** Button in the **Number** group on the **Home** tab.

Conversely, if you write a value with a % sign in a cell, then Excel will recognise it as a percentage:

- For example, write in a cell: 25%.
- Select this cell and open the
**Format**button menu in the**Cells**group on the**Home**tab of the Ribbon. - Click on the
**Format Cells...**button. The**Format Cells**dialog box is opened. - Click on the
**Number**tab, then on**General**in the**Category**list. - Confirm with the
**OK**button. - Note that the value displayed is 0.25.