How do I get excel to calculate ticked boxes as a percentage

[Shanaya_98]

I have inputted check boxes in a table on excel from the Developer tab and I want, at the bottom of my table, for a formula to tell me the percentage of how much is completed.

I have used the formula:

=COUNTIF(B6:B36,1)/COUNTA(B6:B36)

I have also tried various other formulas similar to this one though they are all pulling the error message

#DIV/0!

Will the fact I have entered in the check boxes from the developer tab mean that the formula won't work, is there anything I need to do with the check boxes to make sure they're in the correct field?

Please help!

[#2]

@Shanaya_98 

The error message tells you that cells B6:B36 are empty.  This means that the controls have not been linked to cells in the correct range.  Both the new 365 controls and the traditional form controls return TRUE/FALSE rather than 0/1 so the formula would need to read

= COUNTIF(checkmarks, TRUE) / COUNTA(checkmarks)