-40% is the change from 810 to 486
Calculation steps:
[( 486 - 810 ) ÷ 810] x 100 = -40%
Formula
Percentage change = [(486 - 810) / 810] x 100
Subtract the new number by the original number
486 - 810 = -324
-324 ÷ 810 = -0.4
-0.4 x 100 = -40%
Example