Options Premium Calculator
Enter spot, strike, IV, and days to expiry for a call or put — get theoretical premium, intrinsic vs. time value split, full Greeks, and ±2% spot scenarios.
Options Premium Calculator
Estimate option premium using Black-Scholes with full Greeks — Delta, Gamma, Theta, Vega, Rho.
| Greek | Value | Per |
|---|---|---|
| Δ Delta | 0.5410 | ₹1 spot move |
| Γ Gamma | 0.000533 | ₹1 spot move (delta change) |
| Θ Theta | -12.1563 | calendar day |
| ν Vega | 19.7092 | 1% IV change |
| ρ Rho | 5.3116 | 1% rate change |
| Spot Move | Approx. Premium | Change |
|---|---|---|
| -2% | ₹129.03 | ₹-201.60 |
| -1% | ₹214.15 | ₹-116.48 |
| Current | ₹330.63 | — |
| +1% | ₹478.80 | +₹148.17 |
| +2% | ₹655.79 | +₹325.16 |
About Options Premium Calculator
The Options Premium Calculator uses the Black-Scholes model to estimate the theoretical fair value of European call and put options. Developed in 1973 by Fischer Black, Myron Scholes, and Robert Merton, it remains the foundational pricing model for options worldwide and is directly applicable to Nifty and BankNifty index options — both of which are European-style (exercisable only at expiry).
The model takes five inputs: spot price, strike price, days to expiry, implied volatility (IV), and the risk-free rate. The output is not just a premium — it also includes the full set of option Greeks (Delta, Gamma, Theta, Vega, Rho) that quantify how the premium changes with each underlying variable. Understanding Greeks is essential for managing risk in an options position.
The calculator shows the theoretical premium split into intrinsic value (how deep the option is in-the-money) and time value (the probability premium the market assigns to further movement). At-the-money options carry zero intrinsic value but maximum time value. Deep in-the-money options are mostly intrinsic; deep out-of-the-money options are pure time value.
A Spot Scenarios table shows estimated premium at ±1% and ±2% spot moves — useful for quick P&L estimation before placing a trade. Note that Black-Scholes assumes constant implied volatility, no dividends, and European exercise. For American-style stock options or very short-dated contracts (0 DTE), deviations from model price are common.
How to Use the Options Premium Calculator
Select CALL (CE) or PUT (PE) using the toggle at the top of the input panel.
Enter Spot Price (current index or stock price) and Strike Price (the option contract's strike).
Set Days to Expiry using the quick presets (Expiry Day, 1d, 7d, 15d, 30d) or enter a custom value.
Enter Implied Volatility — use the presets (10%, 15%, 20%, 30%) or fetch IV from your broker's option chain.
The theoretical premium, intrinsic value, time value, and all Greeks update instantly. The Moneyness badge (ATM/ITM/OTM) appears in the result card header.
Pro Tips
Time decay (Theta) accelerates exponentially as expiry approaches, especially for ATM options. Option buyers should be aware that the last few days before expiry can wipe out most of an ATM premium even if spot barely moves.
Absolute IV of 20% may be cheap or expensive depending on the index's historical range. Always compare current IV to its 52-week high and low (IV Rank / IV Percentile) to judge whether buying or selling options makes sense.
An option's Delta is approximately equal to its probability of expiring in-the-money. A 0.30 Delta call has roughly a 30% chance of expiring ITM according to Black-Scholes. Use this to select strikes aligned with your conviction level.
Frequently Asked Questions
What is the Black-Scholes model?
Black-Scholes is a mathematical formula that calculates the theoretical fair price of European options. It models the underlying asset price as a geometric Brownian motion and derives a closed-form solution for call and put premiums using five variables: spot price, strike, time to expiry, volatility, and risk-free rate.
What are option Greeks and why do they matter?
Greeks measure the sensitivity of an option's premium to changes in market variables. Delta measures sensitivity to spot price; Gamma is the rate of change of Delta; Theta measures time decay per day; Vega measures sensitivity to a 1% change in IV; Rho measures sensitivity to the risk-free rate. Together they help traders understand and hedge their positions.
Why does the calculator show theoretical premium, not market premium?
Market premiums can deviate from theoretical values due to supply-demand imbalance, bid-ask spreads, and skew (the market charging different IVs for different strikes). The theoretical premium is the "fair value" — deviations from it are where traders find edge or mispricing.
Can I use this for Nifty and BankNifty options?
Yes — both Nifty 50 and BankNifty options are European-style (no early exercise), making Black-Scholes directly applicable. Enter the index level as spot price, the option's strike, days remaining to weekly/monthly expiry, and the IV from NSE's option chain for the corresponding strike.
What risk-free rate should I use for Indian options?
The prevailing RBI repo rate is the standard proxy. As of 2025–26, 6.5% is an appropriate default. The rate has a small effect on premiums (captured by Rho), mostly relevant for longer-dated options and deep ITM strikes.
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