-37% is the change from 800 to 504
Calculation steps:
[( 504 - 800 ) ÷ 800] x 100 = -37%
Formula
Percentage change = [(504 - 800) / 800] x 100
Subtract the new number by the original number
504 - 800 = -296
-296 ÷ 800 = -0.37
-0.37 x 100 = -37%
Example