To find a percentage of a value: `=A1*B1%`
To find a percentage of a total: `=Part/Total`
To convert a decimal to a percentage: `=A1*100%`
To calculate percentage increase: `=(New-Old)/Old`
To calculate percentage decrease: `=(Old-New)/Old`
To find what percent one number is of another: `=A1/B1`
To format a result as a percentage: use the Percent Style button or `Ctrl+Shift+%`
To calculate 20% of 500: `=500*20%`
To calculate percentage difference: `=(A1-B1)/B1`
To display a percentage result in Excel: format the cell as Percentage