3965% is the change from 20 to 813
Calculation steps:
[( 813 - 20 ) ÷ 20] x 100 = 3965%
Formula
Percentage change = [(813 - 20) / 20] x 100
Subtract the new number by the original number
813 - 20 = 793
793 ÷ 20 = 39.65
39.65 x 100 = 3965%
Example