540% is the change from 20 to 128
Calculation steps:
[( 128 - 20 ) ÷ 20] x 100 = 540%
Formula
Percentage change = [(128 - 20) / 20] x 100
Subtract the new number by the original number
128 - 20 = 108
108 ÷ 20 = 5.4
5.4 x 100 = 540%
Example