OptionPayoffCalc is a free set of options calculators built by an independent options trader. It started as a personal tool to check covered calls and cash-secured puts before placing trades, and grew into a small collection of calculators for common strategies.
Theoretical option prices and Greeks use the Black-Scholes model with a continuous dividend yield. Probability of profit assumes a lognormal distribution of the stock price at expiration based on the implied volatility you enter. All calculations run locally in your browser; nothing you type is sent to a server.
The site is free to use, with no sign-up. It is supported by advertising.
For educational purposes only. Not financial advice. Options involve risk and are not suitable for all investors.