54.12% is the change from 255 to 393
Calculation steps:
[( 393 - 255 ) ÷ 255] x 100 = 54.12%
Formula
Percentage change = [(393 - 255) / 255] x 100
Subtract the new number by the original number
393 - 255 = 138
138 ÷ 255 = 0.5411764705882353
0.5411764705882353 x 100 = 54.12%