-86.5% is the change from 400 to 54
Calculation steps:
[( 54 - 400 ) ÷ 400] x 100 = -86.5%
Formula
Percentage change = [(54 - 400) / 400] x 100
Subtract the new number by the original number
54 - 400 = -346
-346 ÷ 400 = -0.865
-0.865 x 100 = -86.5%
Example