800% is the change from 45 to 405
Calculation steps:
[( 405 - 45 ) ÷ 45] x 100 = 800%
Formula
Percentage change = [(405 - 45) / 45] x 100
Subtract the new number by the original number
405 - 45 = 360
360 ÷ 45 = 8
8 x 100 = 800%
Example