To complete this calculation in excel you need to use a simple formula in a cell as below:

=YourNumber*(1-0.2)

**Examples of How To Take 20% in Excel**

Using a number eg 20:

=20*(1-0.2)

Using a cell eg a1:

=A1*.8

If the percentage to be deducted is found in another cell (say B1), then you can format that cell as % and use this sort of formula.

=A1*(1-B1)

**More Advanced Techniques for 20% Calculations**

=Round(A1*.8,0)

If the percentage to be deducted is found in another cell (say B1), then you can format that cell as % and use this sort of formula.