2500% is the change from 12 to 312
Calculation steps:
[( 312 - 12 ) ÷ 12] x 100 = 2500%
Formula
Percentage change = [(312 - 12) / 12] x 100
Subtract the new number by the original number
312 - 12 = 300
300 ÷ 12 = 25
25 x 100 = 2500%
Example