-40.19% is the change from 821 to 491
Calculation steps:
[( 491 - 821 ) ÷ 821] x 100 = -40.19%
Formula
Percentage change = [(491 - 821) / 821] x 100
Subtract the new number by the original number
491 - 821 = -330
-330 ÷ 821 = -0.40194884287454324
-0.40194884287454324 x 100 = -40.19%