64.71% is the change from 255 to 420
Calculation steps:
[( 420 - 255 ) ÷ 255] x 100 = 64.71%
Formula
Percentage change = [(420 - 255) / 255] x 100
Subtract the new number by the original number
420 - 255 = 165
165 ÷ 255 = 0.6470588235294118
0.6470588235294118 x 100 = 64.71%