85.71% is the change from 280 to 520
Calculation steps:
[( 520 - 280 ) ÷ 280] x 100 = 85.71%
Formula
Percentage change = [(520 - 280) / 280] x 100
Subtract the new number by the original number
520 - 280 = 240
240 ÷ 280 = 0.8571428571428571
0.8571428571428571 x 100 = 85.71%