How do you calculate percentage in excel?

For example;

I have 770 in m63 and I want to add 15% in m64 but I always get errors everytime I do this...

=sum(m63:m64) or

=m63+m64

either error or ######

please help me!!!How do you calculate percentage in excel?
"=m63*1.15"How do you calculate percentage in excel?
######### indicates that the cell/column is not wide enought to display the number. You can widen the column manually or AutoSize it.How do you calculate percentage in excel?
If you are trying to add 15% of 770 to 770 (885.5) then you would need your formula to read:



=m63*(m64+1)