19.76% is the change from 420 to 503
Calculation steps:
[( 503 - 420 ) ÷ 420] x 100 = 19.76%
Formula
Percentage change = [(503 - 420) / 420] x 100
Subtract the new number by the original number
503 - 420 = 83
83 ÷ 420 = 0.1976190476190476
0.1976190476190476 x 100 = 19.76%