2575% is the change from 12 to 321
Calculation steps:
[( 321 - 12 ) ÷ 12] x 100 = 2575%
Formula
Percentage change = [(321 - 12) / 12] x 100
Subtract the new number by the original number
321 - 12 = 309
309 ÷ 12 = 25.75
25.75 x 100 = 2575%
Example