20.31% is the change from 64 to 77
Calculation steps:
[( 77 - 64 ) ÷ 64] x 100 = 20.31%
Formula
Percentage change = [(77 - 64) / 64] x 100
Subtract the new number by the original number
77 - 64 = 13
13 ÷ 64 = 0.203125
0.203125 x 100 = 20.31%
Example