-60.22% is the change from 646 to 257
Calculation steps:
[( 257 - 646 ) ÷ 646] x 100 = -60.22%
Formula
Percentage change = [(257 - 646) / 646] x 100
Subtract the new number by the original number
257 - 646 = -389
-389 ÷ 646 = -0.6021671826625387
-0.6021671826625387 x 100 = -60.22%