100% is the change from 257 to 514
Calculation steps:
[( 514 - 257 ) ÷ 257] x 100 = 100%
Formula
Percentage change = [(514 - 257) / 257] x 100
Subtract the new number by the original number
514 - 257 = 257
257 ÷ 257 = 1
1 x 100 = 100%
Example