4055% is the change from 20 to 831
Calculation steps:
[( 831 - 20 ) ÷ 20] x 100 = 4055%
Formula
Percentage change = [(831 - 20) / 20] x 100
Subtract the new number by the original number
831 - 20 = 811
811 ÷ 20 = 40.55
40.55 x 100 = 4055%
Example