309.76% is the change from 123 to 504
Calculation steps:
[( 504 - 123 ) ÷ 123] x 100 = 309.76%
Formula
Percentage change = [(504 - 123) / 123] x 100
Subtract the new number by the original number
504 - 123 = 381
381 ÷ 123 = 3.097560975609756
3.097560975609756 x 100 = 309.76%