2040% is the change from 30 to 642
Calculation steps:
[( 642 - 30 ) ÷ 30] x 100 = 2040%
Formula
Percentage change = [(642 - 30) / 30] x 100
Subtract the new number by the original number
642 - 30 = 612
612 ÷ 30 = 20.4
20.4 x 100 = 2040%
Example