STT calculator: securities transaction tax by segment

This STT calculator estimates securities transaction tax, a tax on specified securities trades, from your prices and quantity. From 1 April 2026, equity futures sales attract 0.05% and option sales attract 0.15% of premium. Exercised options attract 0.15% on intrinsic value, the exercise value of the option, payable by the purchaser. The form above estimates a buy-and-sell trade; it has no exercise-settlement option or historical transaction-date selector.

Current STT rates and the value each uses

NSE/FATAX/73524, dated 31 March 2026, confirms the effective date. STT is a statutory transaction tax. It is distinct from brokerage, exchange fees, stamp duty and tax on your income. A profitable trade and a losing trade can both generate STT because the base is the taxable transaction value.

These rows describe the specified equity and equity-derivative cases. Do not apply a delivery-share row automatically to a fund unit or another asset. The calculator's segment menu is narrower than the full statutory table.

How to enter this page's buy-and-sell trade

Select Segment from Equity Delivery, Equity Intraday, Futures (F&O) or Options (F&O). Enter Buy Price and Sell Price in rupees per unit. For an option, both prices should be option premiums. For a future, they should be futures prices. The underlying index level is not the premium value used for an option sale.

Quantity (units per lot) and Number of Lots multiply together. For cash shares, use the share count as Quantity and 1 as Number of Lots. For a derivative, use the exchange quantity for the exact contract series and the number of lots actually traded. The stored quantity is only a default; verify your contract independently.

The tool displays Total Turnover, Gross P&L, Brokerage, STT / CTT, Exchange Charges, SEBI Charges, GST, Stamp Duty, DP Charges, Total Charges, Net P&L, Breakeven Move and Charges % of Turnover. P&L means profit and loss; GST is goods and services tax. DP Charges refers to depository charges for shares held in demat. The extra fee cards come from built-in assumptions with no broker selector. They are not a verified bill for your account.

Use the STT / CTT card for the selected equity or equity-derivative tax subtotal. Total Turnover adds buy and sell values. Futures and traded-option STT use the sell value only, so applying their rate to that combined turnover would overstate STT.

Worked option-sale example matching the calculator

Here is a fictional option round trip: choose Options (F&O), Buy Price ₹100, Sell Price ₹120, Quantity 100 units and Number of Lots 1. This quantity is an example assumption rather than a named exchange lot. The sale premium value is ₹120 × 100 × 1 = ₹12,000.

STT is ₹12,000 × 0.15 ÷ 100 = ₹18. This matches the STT / CTT output for those inputs. Total Turnover is (₹100 + ₹120) × 100 = ₹22,000, while Gross P&L is (₹120 − ₹100) × 100 = ₹2,000. Those are different amounts with different purposes.

The ₹18 subtotal is not the complete trade cost. The other fee cards reduce the gross result under the tool's assumptions. For a reconciliation, use actual broker records and the applicable charges, rather than treating the displayed Net P&L as your final account result.

Why delivery equity charges both sides

For a separate made-up share trade, buy 100 shares at ₹500 and sell them at ₹510 using Equity Delivery. Purchase value is ₹50,000 and sale value ₹51,000. STT is ₹50 on purchase plus ₹51 on sale, or ₹101 in total. This example isolates STT and excludes other fees.

Selecting Intraday would apply the intraday sale rule instead. That is a different transaction category, not simply a cheaper tax setting for a delivery trade. Choose the category that reflects what actually happened. The brokerage and charges guide explains why a contract note carries several separate deductions.

Exercise tax is separate from an option sale

A trader who buys an option and later sells it pays sale-side STT on that sale premium. If an option is instead exercised in the money, the exercise rule applies to the purchaser on intrinsic value. It is therefore inaccurate to say that an option buyer can never pay STT. NSE's STT page contains conflicting wording: its tax-value definition says intrinsic value, while a later calculation paragraph says settlement price. The example below follows the explicit intrinsic-value definition, which Zerodha's current charges table also states. Confirm the actual exercise debit with your broker.

For a separate fictional settlement example, suppose total taxable intrinsic value is ₹20,000. Exercise STT is ₹20,000 × 0.15 ÷ 100 = ₹30. That total is a hand calculation, not an output supported by this form. The form has no strike, settlement-price or exercise-category inputs.

Do not enter a settlement index as Sell Price under Options to approximate exercise. That would tax it as option-sale premium. The weekly expiry explanation distinguishes an expired contract's exercise value from an earlier market sale.

Limits when checking an actual bill

No transaction date can be selected, so this page does not price older trades using older rules. It also assumes matching buy and sell quantities. It cannot reconstruct an order traded in parts or several sales at different prices. Reconcile actual executions before using an average.

Displayed money cards are rounded, while the calculation retains intermediate values. Small fee cards may therefore fail to add to the displayed total. The broker's final contract note and statement remain the records to compare. The F&O cost tool addresses a separate combined-cost question, with its own assumptions.

Zero or cleared price and quantity fields can be replaced by positive example defaults. In particular, entering a zero option exit does not model an option expiring worthless correctly. Check the inputs and resulting turnover, and keep settlement outside this round-trip form.

STT calculator questions

Sources

• NSE: notified STT rates and commencement date (checked 15 October 2026).
• NSE: premium and intrinsic-value tax bases (checked 15 October 2026).
• Zerodha: exercise STT charged on intrinsic value (checked 15 October 2026).