80% is the change from 455 to 819
Calculation steps:
[( 819 - 455 ) ÷ 455] x 100 = 80%
Formula
Percentage change = [(819 - 455) / 455] x 100
Subtract the new number by the original number
819 - 455 = 364
364 ÷ 455 = 0.8
0.8 x 100 = 80%
Example