112.5% is the change from 400 to 850
Calculation steps:
[( 850 - 400 ) ÷ 400] x 100 = 112.5%
Formula
Percentage change = [(850 - 400) / 400] x 100
Subtract the new number by the original number
850 - 400 = 450
450 ÷ 400 = 1.125
1.125 x 100 = 112.5%
Example