-64% is the change from 50 to 18
Calculation steps:
[( 18 - 50 ) ÷ 50] x 100 = -64%
Formula
Percentage change = [(18 - 50) / 50] x 100
Subtract the new number by the original number
18 - 50 = -32
-32 ÷ 50 = -0.64
-0.64 x 100 = -64%
Example