300% is the change from 100 to 400
Calculation steps:
[( 400 - 100 ) ÷ 100] x 100 = 300%
Formula
Percentage change = [(400 - 100) / 100] x 100
Subtract the new number by the original number
400 - 100 = 300
300 ÷ 100 = 3
3 x 100 = 300%
Example