Options Greeks Calculator
See delta, gamma, theta, vega, and rho for any call or put using the Black-Scholes model. Understand how an option price reacts to stock moves, time decay, and changes in implied volatility.
Educational purposes only.
Theoretical values from the Black-Scholes model. Real prices may differ due to early exercise, dividends, bid-ask spread, and non-constant volatility. Educational only — not investment advice.
Educational purposes only. These calculators illustrate concepts and do not constitute investment advice. Read our disclaimer
StockCram is not a broker-dealer, investment adviser, or financial institution. All content is for educational and informational purposes only and should not be construed as personalized investment advice. Consult a qualified financial professional before making investment decisions. Past performance does not guarantee future results.How It Works
Enter the contract
Set the stock price, strike, and days to expiration. Pick call or put.
Set implied volatility and rate
Enter the option's implied volatility (from your broker's options chain) and the risk-free rate (a current Treasury yield works fine).
Read the price and Greeks
See the Black-Scholes theoretical price plus delta, gamma, theta, vega, and rho — each in its standard daily / per-1% units.
Check the sensitivity table
See how price and the Greeks shift if the stock moves up or down. This is how options actually behave when the market moves.
Frequently Asked Questions
The Greeks are five numbers that describe how an option price reacts to different inputs. Delta measures sensitivity to the stock price, gamma measures how delta itself changes, theta measures time decay per day, vega measures sensitivity to implied volatility (per 1% move), and rho measures sensitivity to interest rates. They are calculated from the Black-Scholes model.
This calculator uses the Black-Scholes formula for European options. It assumes no dividends, constant volatility, and no early exercise. Real US equity options are American-style and may differ slightly, especially deep in the money or near a dividend date, but Black-Scholes is the standard reference price used across the industry.
A delta of 0.50 means the option price moves roughly $0.50 for every $1 move in the underlying stock. At-the-money options have deltas near 0.50 (calls) or -0.50 (puts). Deep in-the-money calls approach 1.0, and deep out-of-the-money calls approach 0. Delta also approximates the rough probability the option finishes in the money.
Theta is shown per calendar day and is negative for long options because time decay erodes value as expiration approaches. A theta of -0.05 means the option loses about 5 cents of value per day, all else equal. Theta accelerates in the final 30 days before expiration, especially for at-the-money options.
Vega measures how much the option price changes for a 1% change in implied volatility. A vega of 0.15 means the option gains $0.15 if IV rises 1%, and loses $0.15 if IV drops 1%. Vega is highest for at-the-money options with more time to expiration. Understanding vega is key to spotting IV crush after earnings.
Gamma is the rate of change of delta. A high gamma means delta swings quickly as the stock moves, which can be good (rapid profit acceleration) or bad (fast losses on the wrong side). Gamma is highest for at-the-money options near expiration. Long options have positive gamma; short options have negative gamma.
Black-Scholes is a model, not a perfect predictor. Real-world prices can differ due to early-exercise premium, dividends, supply/demand on the bid-ask spread, and the fact that volatility is not actually constant. Use Greeks for risk understanding and relative comparison rather than precise dollar projections.