1850% is the change from 20 to 390
Calculation steps:
[( 390 - 20 ) ÷ 20] x 100 = 1850%
Formula
Percentage change = [(390 - 20) / 20] x 100
Subtract the new number by the original number
390 - 20 = 370
370 ÷ 20 = 18.5
18.5 x 100 = 1850%
Example