20% is the change from 100 to 120
Calculation steps:
[( 120 - 100 ) ÷ 100] x 100 = 20%
Formula
Percentage change = [(120 - 100) / 100] x 100
Subtract the new number by the original number
120 - 100 = 20
20 ÷ 100 = 0.2
0.2 x 100 = 20%
Example