3240% is the change from 15 to 501
Calculation steps:
[( 501 - 15 ) ÷ 15] x 100 = 3240%
Formula
Percentage change = [(501 - 15) / 15] x 100
Subtract the new number by the original number
501 - 15 = 486
486 ÷ 15 = 32.4
32.4 x 100 = 3240%
Example