1505% is the change from 20 to 321
Calculation steps:
[( 321 - 20 ) ÷ 20] x 100 = 1505%
Formula
Percentage change = [(321 - 20) / 20] x 100
Subtract the new number by the original number
321 - 20 = 301
301 ÷ 20 = 15.05
15.05 x 100 = 1505%
Example