For your example, let's take the two way odds 3,05 and 1,4
First you need to calculate the PAYOUT of the odds :
So we are gonna convert this odds to probabilities :
1/3,05 = 0,327868852
1/1,4 = 0,714285714
PAYOUT = (1 / (0,327868852 + 0,714285714)) * 100 = 95,95505618 %
PROFIT MARGIN = 100 - PAYOUT = 4,04494382 = 4,05 (Rounded to be exact)
And as you can see this is the same number shown by Odds Wizard.
