-60.28% is the change from 647 to 257
Calculation steps:
[( 257 - 647 ) ÷ 647] x 100 = -60.28%
Formula
Percentage change = [(257 - 647) / 647] x 100
Subtract the new number by the original number
257 - 647 = -390
-390 ÷ 647 = -0.6027820710973725
-0.6027820710973725 x 100 = -60.28%