To calculate percent of a total ie. Format the calculation as a percentage by using the icon on the Home tab. For example if you have a column containing numbers and want to calculate 10 of one of those numbers enter 10 in another cell then use a formula using the asterisk as the multiplication operator.
You would enter a formula in the of Grand Total column to divide the value in the Total Cost column by the grand total then format the result as a percentage.
How to calculate the percentage of grand total in Excel In many cases you might need to calculate the percentage of Grand Total. In Excel you can do it with the blink of an eye. In the example shown the formula in D6 is. The result is formatted with Percentage number format to show 25 10 etc.