-40% is the change from 100 to 60
Calculation steps:
[( 60 - 100 ) ÷ 100] x 100 = -40%
Formula
Percentage change = [(60 - 100) / 100] x 100
Subtract the new number by the original number
60 - 100 = -40
-40 ÷ 100 = -0.4
-0.4 x 100 = -40%
Example