250% is the change from 40 to 140
Calculation steps:
[( 140 - 40 ) ÷ 40] x 100 = 250%
Formula
Percentage change = [(140 - 40) / 40] x 100
Subtract the new number by the original number
140 - 40 = 100
100 ÷ 40 = 2.5
2.5 x 100 = 250%
Example