-20% is the change from 180 to 144
Calculation steps:
[( 144 - 180 ) ÷ 180] x 100 = -20%
Formula
Percentage change = [(144 - 180) / 180] x 100
Subtract the new number by the original number
144 - 180 = -36
-36 ÷ 180 = -0.2
-0.2 x 100 = -20%
Example