149.03% is the change from 257 to 640
Calculation steps:
[( 640 - 257 ) ÷ 257] x 100 = 149.03%
Formula
Percentage change = [(640 - 257) / 257] x 100
Subtract the new number by the original number
640 - 257 = 383
383 ÷ 257 = 1.490272373540856
1.490272373540856 x 100 = 149.03%