66.15% is the change from 257 to 427
Calculation steps:
[( 427 - 257 ) ÷ 257] x 100 = 66.15%
Formula
Percentage change = [(427 - 257) / 257] x 100
Subtract the new number by the original number
427 - 257 = 170
170 ÷ 257 = 0.6614785992217899
0.6614785992217899 x 100 = 66.15%