103.14% is the change from 255 to 518
Calculation steps:
[( 518 - 255 ) ÷ 255] x 100 = 103.14%
Formula
Percentage change = [(518 - 255) / 255] x 100
Subtract the new number by the original number
518 - 255 = 263
263 ÷ 255 = 1.031372549019608
1.031372549019608 x 100 = 103.14%