Margin Calculator

Initial margin for an Indian futures or short-option position is SPAN margin plus exposure margin, both collected upfront before you can enter. SPAN is the exchange's scenario-based number: it revalues your position across an array of price and volatility moves and takes the worst-case loss as the margin, so it is a 99 percent one-day value-at-risk figure that the clearing corporation updates several times a session from parameter files. Exposure margin is a smaller flat percentage of the notional value added on top. This calculator does not run the exchange SPAN engine and cannot, because that needs the live parameter files. It gives an indicative estimate using a transparent, editable percentage of contract value, with the SPAN and exposure split shown as components. Treat every figure here as an indicative estimate and confirm the live number with your broker's SPAN calculator before you trade.

SPAN, the Standard Portfolio Analysis of Risk, is the core initial-margin number on a derivatives position. Rather than a fixed percentage, it revalues the position across a grid of scenarios, the underlying moving up and down by set steps and volatility rising and falling, and sets the margin to the largest loss in that grid, aiming to cover a 99 percent worst case over one day. Because the inputs to that grid, the price scan range and the volatility scan range, are published by the exchange and refreshed through the session, the same contract can require a different SPAN margin in the afternoon than it did at the open, and requirements typically rise when volatility rises. That is why no static percentage can be exact: a percentage-of-contract-value model like the one here is a snapshot proxy, useful for sizing and for seeing the leverage, not a substitute for the live scenario computation your broker runs.

They are the two components of the initial margin. SPAN margin is the scenario-based core, computed from the worst-case one-day loss across the exchange's price and volatility grid, and it is the larger and more variable of the two. Exposure margin is an additional buffer levied as a flat percentage of the notional value of the position, indicatively around 3 percent for index positions, to cover risks the scenario grid does not, such as a move beyond the scanned range. Added together they are the total initial margin you must have upfront to hold the position. This tool shows both as indicative components of one editable total percentage, so you can see roughly how the buffer sits on top of the scenario core; the exact split on a live trade comes from your broker's SPAN calculator.

As an indicative figure, total initial margin on an index futures lot commonly runs in the low double digits as a percentage of contract value, roughly 10 to 16 percent depending on the index and current volatility, which is an implied leverage of about 6 to 10 times. Take Nifty at 24,000 with the January 2026 lot size of 65: the contract value is 15,60,000 rupees, and at an indicative 12 percent the total initial margin is about 1,87,200 rupees, an implied leverage near 8.3 times. Bank Nifty, being more volatile, tends to sit a little higher as a percentage. These are indicative estimates only, they move with volatility, and the exact rupee margin for a live order is whatever your broker's SPAN calculator shows at that moment. Use this to understand the scale and the leverage, not to fund an account to the paisa.

Because your broker's calculator uses the live exchange SPAN parameter files and this one uses a transparent percentage model. Real SPAN is recomputed several times a day from the exchange's current price scan range and volatility scan range, so the number drifts through the session and jumps when volatility jumps. A fixed percentage of contract value cannot track that, and it deliberately does not try. It also does not model the margin benefit on hedged or spread positions, where a defined-risk structure like a spread requires far less margin than the sum of its legs. So this tool will differ, sometimes materially, from a live quote. That is the honest limitation: it is an indicative estimate for understanding scale and leverage, and the live figure to fund and trade on is your broker's.

Buying an option and writing an option are opposite on margin. When you buy a call or a put, there is no SPAN margin: you pay the full premium upfront, that debit is the entire cost, and it is also the most you can lose, so the risk is defined. When you write, or sell, an option, you collect the premium but you must post SPAN plus exposure margin on the position, an amount in the same order as a futures margin because your loss on the wrong side is open-ended. That asymmetry is the whole point. The buyer pays a small, fixed, known amount for a capped loss; the writer takes in a small premium and posts a large margin against a potentially large loss. This calculator applies the full premium as the outlay for buying, and the indicative SPAN plus exposure model for writing, and it flags that a real multi-leg structure such as a straddle or a spread gets a margin treatment it does not model.

Peak margin is a monitoring rule that removed most intraday over-leverage. Instead of checking your margin only at end of day, the clearing corporation takes four random snapshots of your margin requirement during the session and holds you to the highest one. You must have the full upfront margin, SPAN plus exposure, available at all times, not just at entry, which is why brokers can no longer offer the large intraday multiples they once did and eligible intraday leverage is now capped near five times. If your margin falls short at any snapshot, a short-collection penalty applies, on a scale of about 0.5 to 5 percent of the shortfall depending on size and frequency, charged to the client. The practical effect is that the margin the tool estimates is not a one-time entry cost: it is capital that must stay posted for the life of the position.

Yes, on two counts, which is the most dangerous thing a beginner underestimates. First, mark to market, or MTM: at the end of each day open futures positions are settled to the closing price, so a loss is debited from your account in cash that evening and a gain credited, and if the debit takes you below the required margin you get a margin call to top up before the next session or the position is squared off. Second, the margin requirement itself can rise: SPAN margin increases when volatility rises, and the exchange can levy additional or special margins in stressed conditions, so a position that needed a given margin at entry can demand more the next day even if price has not moved your way. Posted margin is a living requirement, not a deposit you forget about. That is a core reason leveraged positions get liquidated at the worst possible time.

Leverage is symmetric, and that symmetry is the mechanism. If your total initial margin is about 12 percent of contract value, your implied leverage is roughly 8.3 times, and the same arithmetic that lets you control 15,60,000 rupees of Nifty on 1,87,200 rupees of margin means a move in the contract hits your posted capital 8.3 times as hard. A 2 percent adverse gap against the position, an ordinary overnight move, is about a sixth of your posted margin gone before the market opens, and a move of roughly 12 percent against you wipes the posted margin entirely and triggers a call for more. The SEBI FY25 study found over 91 percent of individual traders in the equity derivatives segment were net loss-making, with aggregate net losses near 1,05,603 crore rupees. Leverage did not create bad decisions, but it is the accelerant that turns an ordinary adverse move into a margin call, which is why sizing to the loss, not to the margin the broker will allow, is the whole discipline.