406.25% is the change from 16 to 81
Calculation steps:
[( 81 - 16 ) ÷ 16] x 100 = 406.25%
Formula
Percentage change = [(81 - 16) / 16] x 100
Subtract the new number by the original number
81 - 16 = 65
65 ÷ 16 = 4.0625
4.0625 x 100 = 406.25%
Example