27.68% is the change from 643 to 821
Calculation steps:
[( 821 - 643 ) ÷ 643] x 100 = 27.68%
Formula
Percentage change = [(821 - 643) / 643] x 100
Subtract the new number by the original number
821 - 643 = 178
178 ÷ 643 = 0.27682737169517885
0.27682737169517885 x 100 = 27.68%