Excel will calculate the number of days between the dates entered in cells B3 and A3 and display the result in cell C3. Take your mouse pointer to the lower-right corner of cell C3.

To calculate someone's age in Excel, enter the formula =DATEDIF(A2,TODAY()," y"), where cell A2 contains the date they were born and "Today" is today's date. Press Enter, and Excel will output the ...

Step 4: Another formula you can use to calculate percentage is simply applying the / key in between two cells. For example, to pass a driving theory test, I need to get 80% of the questions correct.