171.24% is the change from 306 to 830
Calculation steps:
[( 830 - 306 ) ÷ 306] x 100 = 171.24%
Formula
Percentage change = [(830 - 306) / 306] x 100
Subtract the new number by the original number
830 - 306 = 524
524 ÷ 306 = 1.7124183006535947
1.7124183006535947 x 100 = 171.24%