250% is the change from 220 to 770
Calculation steps:
[( 770 - 220 ) ÷ 220] x 100 = 250%
Formula
Percentage change = [(770 - 220) / 220] x 100
Subtract the new number by the original number
770 - 220 = 550
550 ÷ 220 = 2.5
2.5 x 100 = 250%
Example