120% is the change from 30 to 66
Calculation steps:
[( 66 - 30 ) ÷ 30] x 100 = 120%
Formula
Percentage change = [(66 - 30) / 30] x 100
Subtract the new number by the original number
66 - 30 = 36
36 ÷ 30 = 1.2
1.2 x 100 = 120%
Example