-69.37% is the change from 839 to 257
Calculation steps:
[( 257 - 839 ) ÷ 839] x 100 = -69.37%
Formula
Percentage change = [(257 - 839) / 839] x 100
Subtract the new number by the original number
257 - 839 = -582
-582 ÷ 839 = -0.6936829558998808
-0.6936829558998808 x 100 = -69.37%