331.25% is the change from 80 to 345
Calculation steps:
[( 345 - 80 ) ÷ 80] x 100 = 331.25%
Formula
Percentage change = [(345 - 80) / 80] x 100
Subtract the new number by the original number
345 - 80 = 265
265 ÷ 80 = 3.3125
3.3125 x 100 = 331.25%
Example