155.6% is the change from 250 to 639
Calculation steps:
[( 639 - 250 ) ÷ 250] x 100 = 155.6%
Formula
Percentage change = [(639 - 250) / 250] x 100
Subtract the new number by the original number
639 - 250 = 389
389 ÷ 250 = 1.556
1.556 x 100 = 155.6%
Example