50% is the change from 12 to 18
Calculation steps:
[( 18 - 12 ) ÷ 12] x 100 = 50%
Formula
Percentage change = [(18 - 12) / 12] x 100
Subtract the new number by the original number
18 - 12 = 6
6 ÷ 12 = 0.5
0.5 x 100 = 50%
Example