257.42% is the change from 256 to 915
Calculation steps:
[( 915 - 256 ) ÷ 256] x 100 = 257.42%
Formula
Percentage change = [(915 - 256) / 256] x 100
Subtract the new number by the original number
915 - 256 = 659
659 ÷ 256 = 2.57421875
2.57421875 x 100 = 257.42%