12.5% is the change from 120 to 135
Calculation steps:
[( 135 - 120 ) ÷ 120] x 100 = 12.5%
Formula
Percentage change = [(135 - 120) / 120] x 100
Subtract the new number by the original number
135 - 120 = 15
15 ÷ 120 = 0.125
0.125 x 100 = 12.5%
Example