-23.21% is the change from 280 to 215
Calculation steps:
[( 215 - 280 ) ÷ 280] x 100 = -23.21%
Formula
Percentage change = [(215 - 280) / 280] x 100
Subtract the new number by the original number
215 - 280 = -65
-65 ÷ 280 = -0.23214285714285715
-0.23214285714285715 x 100 = -23.21%
Example