The Nifty option position size calculator, worked
An option buyer's risk per lot is (entry premium − stop premium) × lot size. Divide the rupees you will risk by it and truncate: the worked example comes out at 2 lots, and the calculator above opens on it.
The worked example, step by step
- 1% of ₹5,00,000 capital is ₹5,000: the most this one trade may lose at its stop.
- A NIFTY option bought at ₹120 with a stop at ₹90 risks ₹30 a unit. NSE's NIFTY lot is 65 units, so one lot risks 30 × 65 = ₹1,950.
- ₹5,000 ÷ ₹1,950 = 2.56, truncated to 2 lots: a quantity of 130.
- At the stop, 2 lots lose ₹3,900, 0.78% of capital. The premium paid is 120 × 130 = ₹15,600, 3.12% of capital.
Truncate, never round up: 3 lots would risk ₹5,850, more than the ₹5,000 budget. When one lot alone risks more than the budget, the calculator shows 0 lots and says so. A buyer's lots are also capped at what the capital pays for in premium.
A stop premium is a plan, not a promise: an option's price can jump past it, and the most a buyer can lose is the whole premium, ₹15,600 here. Brokerage, taxes and slippage are not included. SEBI's study of individual traders in FY26 classed 93% of them as “Only Options Buyers”, and found that 90% of those incurred losses. Sizing sets how much one trade can take; it does not make the trade a good one.
Nifty futures: lots from index points
A future's risk per lot is the stop distance in index points × the lot size, at ₹1 a point a unit. The example's 40-point stop on NIFTY risks ₹2,600 a lot.
Futures, worked, and the contract value
An index future's contract value is the index level × the lot size, so each index point is worth ₹1 a unit, and ₹65 a lot on NIFTY.
- The same ₹5,000 budget. A NIFTY future bought at an illustrative 25,000, with a stop at 24,960, risks 40 points.
- One lot risks 40 × 65 = ₹2,600.
- ₹5,000 ÷ ₹2,600 = 1.92, truncated to 1 lot, a quantity of 65, risking ₹2,600, 0.52% of capital.
- That one lot's contract value is 25,000 × 65 = ₹16,25,000, 16.25 lakh: more than three times the ₹5,00,000 capital.
For a short, put the stop above the entry; the arithmetic is the same. Your broker blocks margin for a future, and the calculator does not model it; a stop order can also fill worse than its price in a fast market. The 25,000 is ours, not a quote: type your own entry and stop.
NSE lot sizes today
NIFTY 65, BANKNIFTY 30, FINNIFTY 60, MIDCPNIFTY 120 and NIFTYNXT50 25, from NSE's own market-lot file, read on 29 October 2026.
The lot table, NSE's circular and SEBI's contract-value rule
| Index (NSE's name) | Symbol | Lot | Risk a lot | Lots for ₹5,000 |
|---|---|---|---|---|
| NIFTY 50 | NIFTY | 65 | 30 × 65 = ₹1,950 | 2 |
| NIFTY BANK | BANKNIFTY | 30 | 30 × 30 = ₹900 | 5 |
| NIFTY FINANCIAL SERVICES | FINNIFTY | 60 | 30 × 60 = ₹1,800 | 2 |
| NIFTY MID SELECT | MIDCPNIFTY | 120 | 30 × 120 = ₹3,600 | 1 |
| NIFTY NEXT 50 | NIFTYNXT50 | 25 | 30 × 25 = ₹750 | 6 |
NSE's market-lot file (fo_mktlots.csv) shows the same lot for every series it lists; NIFTY's row runs from NOV-26 to JUN-31. The sizes come from NSE's circular NSE/FAOP/70616 of 3 October 2025, which revised the index lots “in pursuance of SEBI guidelines for periodic revision of lot size”: the revised NIFTY lot applies from the 6 January 2026 weekly expiry and the 27 January 2026 monthly expiry, and NIFTYNXT50's was left unchanged.
Why these numbers: SEBI's circular of 1 October 2024 (SEBI/HO/MRD/TPD-1/P/CIR/2024/132) says “it has been decided that a derivative contract shall have a value not less than Rs. 15 lakhs at the time of its introduction in the market. Further, the lot size shall be fixed in such a manner that the contract value of the derivative on the day of review is within Rs. 15 lakhs to Rs. 20 lakhs.” NSE's circular adds: “For purpose of computation of contract value, the average closing price of the underlying index has been taken for one-month period of September 2025.” So a lot is set in rupees of contract value, not in units, and at a review a rising index can mean a smaller lot.
This page's table is dated. Check NSE's file or your broker's order window before you trade, and use the lot your contract was traded at when you log it.
How to calculate position size in TradingView
TradingView's Long Position and Short Position tools size a trade from your account and your risk. Enter the lot size, and their quantity is in lots.
TradingView's own formula, and how it matches this calculator
TradingView's help page for the two drawing tools, read on 29 October 2026: “In the properties dialog of the instrument, enter your initial account size in the default or selected currency, and the risk amount either in absolute numbers or as a % of your account size. You can also enter the lot size and set leverage, change the entry price, profit or stop level, and quantity precision if needed.”
For a long position it gives the formula: Position Size Qty = min(QtyRisk, QtyLvg), where QtyRisk = (RiskSize / ((EntryPrice – StopPrice) * Point value)) / Lot size and QtyLvg = (Account size * Leverage / EntryPrice) * Point value / Lot size.
That is this calculator's arithmetic. Take a point value of 1, a 1.00 move paying ₹1 a unit, and a lot size of 65. For the worked example, QtyRisk = (5,000 / ((120 − 90) × 1)) / 65 = 2.56 lots, and QtyLvg at a leverage of 1 = (5,00,000 × 1 / 120) × 1 / 65 = 64.1 lots, which is what the capital pays for in premium. The smaller one, 2.56, is the size; this calculator truncates it to 2 whole lots.
On an index or futures chart the entry and stop are in index points, as in the futures mode above. TradingView's page mentions a quantity precision setting but not whether the tool rounds or truncates, so compare its Qty with the whole lots here; if it differs, check the point value TradingView uses for that symbol.
Stocks, CME futures and other markets
The arithmetic is the same everywhere: risk ÷ what one unit, lot or contract loses at the stop, rounded down.
Which calculator for which trade
For cash shares, the stock position size calculator sizes in shares from your risk and stop; its labels are in dollars, but the same arithmetic, risk ÷ the stop distance a share, applies in rupees. For CME contracts such as ES or NQ, the futures position size calculator sizes in contracts from ticks and tick value. For a Turtle-style size from N, the average true range, there is the Turtle position size calculator.
To keep each trade's lot size, lots and R on record in rupees, the trading journal for the Indian market has Lot size and Lots columns and computes the quantity and the risk for you.