Option Margin
Calculator
Estimate the margin to short an NSE option using your own broker's margin percentage — you stay in control of the rate.
Position inputs
Enter the SPAN + exposure % from your broker's margin calculator. Rates are set by NSE/exchange and vary by broker, instrument and volatility — we never hardcode them.
Estimated margin
How it's calculated
This is an estimate of the margin blocked to sell (write) an option. The formula is intentionally simple and broker-rate driven:
- Contract value = spot × lot size.
- Margin per lot = spot × lot size × (total margin % ÷ 100).
- Total margin = margin per lot × number of lots.
The total margin % is the SPAN margin plus the exposure margin — both set by the exchange (NSE) and revised continuously with volatility. They differ by instrument and by broker, so this tool asks you to enter your own rate rather than assuming one. Pull the figure from your broker's margin calculator for the contract you are trading.
Example: spot ₹23,500, lot size 75, total margin 12%. Contract value = 23,500 × 75 = ₹17,62,500. Margin per lot = 17,62,500 × 12 ÷ 100 = ₹2,11,500. For 1 lot, total margin = ₹2,11,500.
Buying an option needs no margin — only the premium. Margin applies to option selling, where your risk is open.
Trade with live data
Live option chains, OI, IV and max pain for every NSE F&O instrument — free on TradePulse.
FAQ
How is option selling margin calculated?
As an estimate, margin = spot × lot size × total margin % ÷ 100, where the total margin % is the SPAN plus exposure percentage quoted by your broker. The exact figure comes from the exchange SPAN file and moves intraday.
Why do I have to enter the margin percentage?
Margin rates are set by NSE, revised continuously, and differ by instrument and broker. We never hardcode a rate. Enter the SPAN + exposure % from your broker's margin calculator for an accurate estimate.
Do I need margin to buy options?
No. Buying an option costs only the premium (premium × lot size). Margin applies to selling or writing options.