-23.36% is the change from 839 to 643
Calculation steps:
[( 643 - 839 ) ÷ 839] x 100 = -23.36%
Formula
Percentage change = [(643 - 839) / 839] x 100
Subtract the new number by the original number
643 - 839 = -196
-196 ÷ 839 = -0.23361144219308702
-0.23361144219308702 x 100 = -23.36%