-49.22% is the change from 642 to 326
Calculation steps:
[( 326 - 642 ) ÷ 642] x 100 = -49.22%
Formula
Percentage change = [(326 - 642) / 642] x 100
Subtract the new number by the original number
326 - 642 = -316
-316 ÷ 642 = -0.49221183800623053
-0.49221183800623053 x 100 = -49.22%