SPAN margin
The core exchange margin for futures and short options, derived by stress-testing your position across 16 market scenarios and taking the worst-case one-day loss.
NubraNubra F&O Margin Calculator
Calculate the required margin for F&O trading. You can also use this tool to calculate margin for option buying or option selling.
Option legsLoading contracts
0 matching contracts
1
What is it
What is an F&O margin?
Margin is the collateral NSE and BSE require before you can take a futures or short-options position - collateral sized to cover the worst plausible one-day loss on that position, not a fee you pay away. It stays blocked in your account for as long as the position is open.
Every F&O position carries a margin requirement made up of two exchange-mandated layers - SPAN margin and exposure margin - calculated fresh each day and often intraday from the underlying's live volatility. Buying options is the one exception: since your maximum loss is capped at the premium paid, no SPAN or exposure margin applies, only the premium itself.
Margin types
The four types of margin
SPAN and exposure margin drive F&O requirements; VaR and extreme loss margin apply on the cash/equity side. All four exist to size collateral to real, quantifiable risk.
Exposure margin
An additional buffer on top of SPAN to cover extreme moves beyond SPAN's scenario set - charged on futures and short options as a percentage of contract value.
Value at Risk (VaR) margin
Used primarily for the cash/equity segment, VaR margin covers the maximum expected loss over a set holding period at a given confidence level, based on historical volatility.
Extreme loss margin
A further cash-market buffer above VaR margin, charged at whichever is higher of 5% of the position's value or 1.5 times the standard deviation of the asset's daily logarithmic returns over the last six months.
How it works
How F&O margin is calculated
For futures and short options, margin is a percentage of contract value split across SPAN and exposure. Offsetting legs on the same underlying earn a spread benefit that lowers the combined requirement.
Contract value (Rs.) = Lot size x Lots x Underlying priceThe notional exposure one leg represents - the base SPAN and exposure margin are calculated against.
Total margin = SPAN margin + Exposure margin - Spread benefitSPAN margin covers the worst-case scenario loss; exposure margin adds a buffer beyond it; spread benefit subtracts the discount earned when offsetting legs reduce net risk. Buying options replaces this with the premium paid instead.
Example
Example: margin for a short Nifty option
Say you sell 1 lot of a Nifty option with the underlying at an illustrative Rs.25,200 and a lot size of 75.
| Input | Value |
|---|---|
| Contract value (75 x Rs.25,200) | Rs.18,90,000 |
| SPAN margin (illustrative 8%) | Rs.1,51,200 |
| Exposure margin (illustrative 2%) | Rs.37,800 |
| Total margin required | Rs.1,89,000 |
The premium received for writing the option is credited separately and doesn't reduce this total - the exchange still requires the full SPAN + exposure amount as collateral regardless of premium collected.
How to use it
4 steps to use the margin calculator
Add your first leg
Pick the exchange, instrument and expiry, then choose the strike, option type and Buy or Sell side for your first option leg.
Set quantity
Enter the number of lots. Lot size auto-fills for common index and stock presets, or enter it directly for any other symbol.
Add more legs for a spread
For multi-leg strategies such as spreads and straddles, add up to twelve option legs. Offsetting legs on the same symbol reduce combined margin through the spread benefit.
Read the combined result
The result panel totals SPAN margin, exposure margin and spread benefit into the total margin required, plus any premium receivable from options you've sold.
Why it matters
Why check margin before you trade
Know your capital requirement before placing an order
See the margin a position will block ahead of time instead of finding out at order entry, so you can size positions to what your account can actually support.
Compare single-leg vs hedged positions
Adding an offsetting leg shows the spread benefit directly, making it easy to see how much margin a hedge saves versus holding each leg standalone.
Separate margin from premium
Buying options blocks premium, not SPAN margin; selling options blocks SPAN + exposure margin and credits premium separately. Keeping these apart avoids miscalculating how much capital a trade really needs.
FAQ
Frequently asked questions
What is margin in F&O trading?
Margin is the collateral the exchange requires you to keep aside before you can take a futures or options position. It is not a fee - it is a good-faith deposit that covers the potential one-day loss on your position, blocked from your available funds until you exit or the position expires.
What is SPAN margin?
SPAN (Standardized Portfolio Analysis of Risk) margin is the core exchange-mandated margin for futures and short options, calculated by running your position through 16 what-if market scenarios and taking the worst-case one-day loss. NSE and BSE publish a fresh SPAN file every day, so the exact figure moves with volatility.
What is exposure margin?
Exposure margin is an additional buffer charged on top of SPAN margin to cover risk beyond SPAN's worst-case scenarios - extreme, low-probability moves. It is typically a smaller percentage of contract value than SPAN and is charged on both futures and short options positions.
Do I need margin to buy options?
No. Buying (going long) a call or put only requires the full option premium upfront - your maximum loss is capped at what you paid, so no SPAN or exposure margin applies. Margin requirements kick in when you write (sell) options or trade futures, where losses are theoretically larger than the premium received.
What is spread or hedge margin benefit?
When two legs of your position offset each other's risk - for example a long and short futures position on correlated instruments, or a calendar spread - the exchange reduces the combined margin below what each leg would need standalone. This spread benefit reflects the lower net risk of a hedged position.
Why does my margin requirement change during the day?
SPAN margin is recalculated from the exchange's SPAN file, which NSE and BSE republish up to six times during an active session as volatility moves. A sharp move in the underlying can raise the SPAN percentage and increase the margin required to hold the same position - this is also why no calculator, including brokers' own, can show a figure that's guaranteed accurate to the minute.
What happens if my margin falls short?
If your available margin drops below the required level - from a mark-to-market loss or a SPAN revision - your broker issues a margin call. If you don't add funds or reduce the position in time, the broker can square off part or all of the position to bring margin utilization back in line.
Margin figures shown by this calculator are illustrative estimates for educational purposes, not live exchange data. SPAN margin is computed from a risk array the exchange revises up to six times during an active session, not a public formula - which is why every F&O margin calculator, including brokers' own tools, publishes an estimate rather than a guaranteed live figure. Always confirm the exact margin required with your broker before placing an order.