34.5% is the change from 400 to 538
Calculation steps:
[( 538 - 400 ) ÷ 400] x 100 = 34.5%
Formula
Percentage change = [(538 - 400) / 400] x 100
Subtract the new number by the original number
538 - 400 = 138
138 ÷ 400 = 0.345
0.345 x 100 = 34.5%
Example