29.5% is the change from 400 to 518
Calculation steps:
[( 518 - 400 ) ÷ 400] x 100 = 29.5%
Formula
Percentage change = [(518 - 400) / 400] x 100
Subtract the new number by the original number
518 - 400 = 118
118 ÷ 400 = 0.295
0.295 x 100 = 29.5%
Example