309% is the change from 100 to 409
Calculation steps:
[( 409 - 100 ) ÷ 100] x 100 = 309%
Formula
Percentage change = [(409 - 100) / 100] x 100
Subtract the new number by the original number
409 - 100 = 309
309 ÷ 100 = 3.09
3.09 x 100 = 309%
Example