4005% is the change from 20 to 821
Calculation steps:
[( 821 - 20 ) ÷ 20] x 100 = 4005%
Formula
Percentage change = [(821 - 20) / 20] x 100
Subtract the new number by the original number
821 - 20 = 801
801 ÷ 20 = 40.05
40.05 x 100 = 4005%
Example