2450% is the change from 20 to 510
Calculation steps:
[( 510 - 20 ) ÷ 20] x 100 = 2450%
Formula
Percentage change = [(510 - 20) / 20] x 100
Subtract the new number by the original number
510 - 20 = 490
490 ÷ 20 = 24.5
24.5 x 100 = 2450%
Example