How much tax will it cost for importing if I am buying an items outside India?

i am planning to go for an internet shopping and i would like to know how much tax will it cost me again for import the items to india and I am trying to shopped from some US sites means items will be shipped from US?
i am planning to go for an internet shopping and i would like to know how much tax will it cost me again for import the items to india and I am trying to shopped from some US sites means items will be shipped from US? Items will be like clothing items thirts,caps,necklaces etc…
is it includes in the shipping cost or i have to pay an additional amount again