290% is the change from 80 to 312
Calculation steps:
[( 312 - 80 ) ÷ 80] x 100 = 290%
Formula
Percentage change = [(312 - 80) / 80] x 100
Subtract the new number by the original number
312 - 80 = 232
232 ÷ 80 = 2.9
2.9 x 100 = 290%
Example