19.53% is the change from 256 to 306
Calculation steps:
[( 306 - 256 ) ÷ 256] x 100 = 19.53%
Formula
Percentage change = [(306 - 256) / 256] x 100
Subtract the new number by the original number
306 - 256 = 50
50 ÷ 256 = 0.1953125
0.1953125 x 100 = 19.53%