420% is the change from 100 to 520
Calculation steps:
[( 520 - 100 ) ÷ 100] x 100 = 420%
Formula
Percentage change = [(520 - 100) / 100] x 100
Subtract the new number by the original number
520 - 100 = 420
420 ÷ 100 = 4.2
4.2 x 100 = 420%
Example