750% is the change from 30 to 255
Calculation steps:
[( 255 - 30 ) ÷ 30] x 100 = 750%
Formula
Percentage change = [(255 - 30) / 30] x 100
Subtract the new number by the original number
255 - 30 = 225
225 ÷ 30 = 7.5
7.5 x 100 = 750%
Example