-50% is the change from 498 to 249
Calculation steps:
[( 249 - 498 ) ÷ 498] x 100 = -50%
Formula
Percentage change = [(249 - 498) / 498] x 100
Subtract the new number by the original number
249 - 498 = -249
-249 ÷ 498 = -0.5
-0.5 x 100 = -50%
Example