-50.86% is the change from 643 to 316
Calculation steps:
[( 316 - 643 ) ÷ 643] x 100 = -50.86%
Formula
Percentage change = [(316 - 643) / 643] x 100
Subtract the new number by the original number
316 - 643 = -327
-327 ÷ 643 = -0.5085536547433903
-0.5085536547433903 x 100 = -50.86%