33.2% is the change from 500 to 666
Calculation steps:
[( 666 - 500 ) ÷ 500] x 100 = 33.2%
Formula
Percentage change = [(666 - 500) / 500] x 100
Subtract the new number by the original number
666 - 500 = 166
166 ÷ 500 = 0.332
0.332 x 100 = 33.2%
Example