1577.5% is the change from 40 to 671
Calculation steps:
[( 671 - 40 ) ÷ 40] x 100 = 1577.5%
Formula
Percentage change = [(671 - 40) / 40] x 100
Subtract the new number by the original number
671 - 40 = 631
631 ÷ 40 = 15.775
15.775 x 100 = 1577.5%
Example