How to use the F&O margin calculator
- Choose the contract: Nifty, Bank Nifty or a stock. The price, lot size and typical margin rates fill in.
- Choose the position: futures, sell an option or buy an option.
- For a sold index option, choose a normal day or expiry day. On expiry day an extra 2% exposure margin applies.
- Check the SPAN and exposure margin rates. The defaults are typical levels for October 2026. Replace them with the rates your broker shows if you know them.
- Enter the number of lots and your capital to see how much of the account the position takes.
The lot size is the number of units in one contract. For what margin is and why brokers collect it, see what is margin in trading.
How F&O margin is calculated
| Part of the margin | What it covers | Set by |
|---|---|---|
| SPAN margin | The largest one-day loss the position could suffer across the exchange's price and volatility scenarios | NSE Clearing or Indian Clearing Corporation, updated several times a day |
| Exposure margin | A buffer on top of SPAN: 2% of contract value for index F&O, 3.5% or more for stock F&O | The exchange |
| Extra exposure margin on expiry day | 2% of contract value on short index options that expire that day | SEBI rule, from 20 November 2024 |
| Premium | Paid in full by an option buyer, who needs no SPAN or exposure margin | Collected upfront since February 2025 |
Your broker must collect at least the exchange margin before the order goes out. It can ask for more than the exchange minimum, never less.
Margin for one lot at typical rates
The figures below are the calculator's defaults. The rates are assumptions chosen to sit inside the range brokers showed in October 2026, about 10% to 15% of contract value for Nifty futures and short options.
| Position | Contract value | Rates used | Margin |
|---|---|---|---|
| Nifty futures, 25,000 × 65 | ₹16,25,000 | 9% SPAN + 2% exposure | ₹1,78,750 |
| Sell a Nifty at-the-money option, normal day | ₹16,25,000 | 7% + 2% | ₹1,46,250 |
| The same option on its expiry day | ₹16,25,000 | 7% + 2% + 2% | ₹1,78,750 |
| Buy a Nifty 25,000 call at ₹280 | ₹16,25,000 | Premium only | ₹18,200 |
| Bank Nifty futures, 56,000 × 30 | ₹16,80,000 | 8% + 2% | ₹1,68,000 |
| Sell a Bank Nifty at-the-money option | ₹16,80,000 | 6.5% + 2% | ₹1,42,800 |
| Stock futures, ₹1,400 × 500 | ₹7,00,000 | 15% + 3.5% | ₹1,29,500 |
Leverage is the contract value divided by the margin. The Nifty futures lot above has leverage of 9.1×, the short Nifty option 11.1× and the stock future 5.4×. Leverage multiplies a move in the price into a much larger move in your account.
Option selling margin calculator
Selling an option needs margin because the seller's loss has no fixed limit. The buyer of the same option pays only the premium, which is the most a buyer can lose. Use the calculator as an option selling margin calculator by choosing Sell an option: it adds the SPAN and exposure parts and, for index options, the extra margin on expiry day.
SPAN for a sold option depends on how far it is from the money and how volatile the market is. An at-the-money option needs more than a far out-of-the-money one, and margins rise when volatility rises. The table shows the margin on one lot of a sold Nifty option at different SPAN rates.
| SPAN rate | Normal day | Expiry day |
|---|---|---|
| 5% | ₹1,13,750 | ₹1,46,250 |
| 6% | ₹1,30,000 | ₹1,62,500 |
| 7% | ₹1,46,250 | ₹1,78,750 |
| 8% | ₹1,62,500 | ₹1,95,000 |
| 10% | ₹1,95,000 | ₹2,27,500 |
Two sold options are margined as a portfolio, so a short straddle needs less than two separate short legs: about ₹2 lakh to ₹2.4 lakh a lot. Buying a further out-of-the-money option against a sold one caps the loss and cuts the margin sharply.
How a SPAN margin calculator works
SPAN (Standard Portfolio Analysis of Risk) revalues your whole F&O portfolio under 16 scenarios of price and volatility change and takes the worst loss as the SPAN margin. The price scan range sets how far the price moves in those scenarios. When volatility rises, the clearing corporation widens the scan range, and the margin on positions you already hold rises with it, sometimes during the session.
A SPAN margin calculator, such as the one on your broker's website, reads the clearing corporation's latest SPAN file and runs those scenarios on the exact contracts you enter. That is why it gives the exact figure for a spread, a straddle or a basket of legs. This calculator does not read the SPAN file. It applies the percentages you set to the contract value, which is quick for one position and shows the leverage and mark-to-market risk, but treats every position as unhedged.
Exposure margin is added on top of SPAN. For index futures and options it is 2% of contract value. For stock F&O it is the higher of 3.5% and 1.5 times the stock's volatility, so volatile stocks need more.
Zerodha margin calculator
Zerodha's margin calculator on its website uses the latest SPAN file. You add contracts, including several legs together, and it shows the SPAN, exposure and total margin, with the benefit for hedged legs. Kite also shows the required margin in the order window before you place an order. Use it, or the equivalent at Upstox, Fyers, IIFL Capital or Wisdom Capital, for the exact figure on the day you trade.
Use this calculator alongside it to see what the margin means for your account: the share of your capital it takes, how many lots your capital covers and how far the price can move before a loss eats into the margin.
Futures margin and daily losses
Futures profits and losses are settled in cash every day, so the margin is not the most you can lose. It is a deposit that the exchange expects to cover about a day's loss. The calculator shows what a move against one lot of Nifty futures costs.
| Move against you | Nifty points | Loss on one lot | Share of the ₹1,78,750 margin |
|---|---|---|---|
| 1% | 250 | ₹16,250 | 9% |
| 2% | 500 | ₹32,500 | 18% |
| 3% | 750 | ₹48,750 | 27% |
| 5% | 1,250 | ₹81,250 | 45% |
If losses take the account below the margin required, the broker asks for more funds or closes the position. Keep money in the account above the margin for these losses.
Rules that change the margin you need
- Full margin for intraday positions. Since September 2021, brokers must collect the full SPAN and exposure margin for intraday F&O positions, the same as for positions carried overnight.
- Extra margin on expiry day. Since 20 November 2024, short index options expiring that day carry an extra 2% exposure margin.
- No calendar spread benefit on expiry day. Since 1 February 2025, positions in contracts expiring that day get no margin offset against other expiries.
- Premium collected upfront. Since February 2025, option buyers pay the full premium before the order is placed.
- Cash and collateral. Brokers require at least half the margin in cash or cash equivalents. The rest can come from shares you pledge, after a haircut.
Checks before you trade
- Check the exact figure in your broker's margin calculator on the day, because SPAN changes during the session.
- Place the bought leg of a hedge before the sold leg, or the broker blocks the full margin of the short leg first.
- Keep funds above the margin for daily losses, and more before events such as the RBI policy, the Budget or US data.
- On expiry morning, check free margin before the open: a sold option that fitted yesterday may not fit today.
- Size the position by the loss you accept, not by the margin you have; the position size calculator does that.
When you trade through QuantPower, the margin shown before the order comes from your connected broker account, so it matches what the broker will block.
Related calculators
- Brokerage calculator for the charges on a round trip
- STT tax calculator for STT and the other statutory charges
- Position size calculator for the lots that fit your risk per trade
- Option profit calculator for the payoff of a position at expiry
- What is margin in trading for what margin is and why brokers collect it
- Hedge margin benefit for the margin saved by buying a wing
- Pledge shares for margin for using shares you hold as collateral
- Option buying vs selling for how the two sides compare on risk and odds
- Futures vs options for how the two differ on margin and risk
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Frequently asked questions
How is F&O margin calculated?
The clearing corporation works out SPAN margin, the largest one-day loss across its risk scenarios, and the exchange adds exposure margin, 2% of contract value for index F&O. Short index options also carry an extra 2% on their expiry day. Option buyers pay only the premium.
How much margin do I need for one lot of Nifty futures?
About ₹1.6 lakh to ₹2.4 lakh in October 2026, or 10% to 15% of the contract value. At 25,000 and a lot of 65, the contract is worth ₹16,25,000, and 11% of it is ₹1,78,750. Check your broker's figure on the day you trade.
What is the difference between SPAN and exposure margin?
SPAN covers the likely worst one-day loss on your portfolio and changes with volatility and with hedges. Exposure margin is a fixed extra buffer on the contract value, 2% for index F&O and at least 3.5% for stock F&O.
Do I need margin to buy options?
No. A buyer pays the full premium upfront, and that premium is the most the position can lose.
Why did my margin go up during the day?
The clearing corporation updates SPAN several times a session. When volatility rises, the scan range widens and the margin on open positions rises with it.
Is intraday F&O margin lower than overnight margin?
No. Since September 2021, intraday F&O positions need the full SPAN and exposure margin. Intraday positions are squared off before the close, but they need the same margin while they are open.
What happens if my account falls short of margin?
The broker asks you to add funds or reduces the position. If the account is short of the exchange's required margin, the exchange charges a shortfall penalty, which the broker passes on to you.
Sources
- SEBI: measures to strengthen the equity index derivatives framework, 1 October 2024 (extra exposure margin on expiry day, upfront premium, calendar spread on expiry day)
- SEBI: peak margin requirements, phased in up to September 2021
- NSE Clearing: SPAN parameters and exposure margin rules for equity derivatives
- NSE: revision in market lot of index derivative contracts from the January 2026 series (Nifty 65, Bank Nifty 30)
- Broker margin calculators and published margin examples for Nifty and Bank Nifty, checked 17 October 2026