3945% is the change from 20 to 809
Calculation steps:
[( 809 - 20 ) ÷ 20] x 100 = 3945%
Formula
Percentage change = [(809 - 20) / 20] x 100
Subtract the new number by the original number
809 - 20 = 789
789 ÷ 20 = 39.45
39.45 x 100 = 3945%
Example