3842.86% is the change from 21 to 828
Calculation steps:
[( 828 - 21 ) ÷ 21] x 100 = 3842.86%
Formula
Percentage change = [(828 - 21) / 21] x 100
Subtract the new number by the original number
828 - 21 = 807
807 ÷ 21 = 38.42857142857143
38.42857142857143 x 100 = 3842.86%
Example