275% is the change from 12 to 45
Calculation steps:
[( 45 - 12 ) ÷ 12] x 100 = 275%
Formula
Percentage change = [(45 - 12) / 12] x 100
Subtract the new number by the original number
45 - 12 = 33
33 ÷ 12 = 2.75
2.75 x 100 = 275%
Example