One person has tax dues for 1999-2000AY amount 1700/- now he wants to pay it but thats the principle amount due that year, some interst must also be there. How to calculate that, any formula? Simply should I take 1% per month from then till now so in total 16 years meaning 192 months meaning 192% of 1700/- = 3264/- interest alone on 1700/- under just one section. Can anyone clarify if this is ok.