102.4% is the change from 250 to 506
Calculation steps:
[( 506 - 250 ) ÷ 250] x 100 = 102.4%
Formula
Percentage change = [(506 - 250) / 250] x 100
Subtract the new number by the original number
506 - 250 = 256
256 ÷ 250 = 1.024
1.024 x 100 = 102.4%
Example