282.5% is the change from 80 to 306
Calculation steps:
[( 306 - 80 ) ÷ 80] x 100 = 282.5%
Formula
Percentage change = [(306 - 80) / 80] x 100
Subtract the new number by the original number
306 - 80 = 226
226 ÷ 80 = 2.825
2.825 x 100 = 282.5%
Example