How to read it
Each leg is one order
A round trip is two legs, the entry and the exit, and both are charged. STT falls on the sell side of an option or a future, stamp duty on the buy side, the exchange and SEBI charges on both sides, and GST on the exchange charge and on brokerage.
Per unit is what the market has to give back
Total charges divided by the units traded: the points of premium or price that go to costs before any profit. On a small premium it is a large share of the premium.
Exercise has its own STT
A cash settled index option that ends in the money is exercised for its buyer. STT is then charged on the intrinsic value, at 0.15% from 1 Apr 2026 (it was 0.125% before), whatever premium was paid.
Rates carry their date
The rate set in force is chosen at the top and its effective date is printed with the NSE circular numbers. Earlier sets show what the same trade cost before 1 Apr 2026. Rates before 1 Oct 2024 are not in this tool.
Where it is taught
The cost of a trade module walks through the same charges on a dated contract note.
What it leaves out
Brokerage is not statutory: enter your own, and GST at 18% is added on it. Brokers may add platform or other fees, and round each charge. Tax on the profit is a separate matter, covered in Learn module 11.2. The tool does not model a future held to expiry, physical settlement of stock contracts or BSE contracts.