About OptionWit

An independent, free options calculator

OptionWit is a free tool that reprices your option with the Black-Scholes model at every combination of future date and stock price, so you can see what a position is worth before expiry rather than only at it. It exists because most retail options tools either cost money, hide their assumptions, or bury the one number you came for behind a signup wall.

What we believe

Options confuse people for a specific reason: the price moves for three separate reasons at once. The stock moves, time passes, and implied volatility shifts. A tool that only shows a profit-at-expiry diagram hides two of those three forces. Our whole approach is to make all three visible and to show the math behind every figure, because a number you can reproduce is one you can trust.

That leads to a few firm rules:

Show the math. Every worked example in our guides is computed with the same Black-Scholes engine the calculator runs, and the exact formulas are on the methodology page.
Store nothing on a server. The calculator runs entirely in your browser, with no accounts, no server, and no database. Saved positions live only in your browser's local storage, and share links encode numbers in the URL, so nothing you do here reaches a server.
No tracking that needs a banner. Aggregate page counts and a few anonymous interaction counts (whether a visit used the calculator, saved a scenario, or loaded one) use cookieless, privacy-friendly analytics: no cookies, no identities, no personal data, and no ad networks. More on the privacy page.
Not advice. We show you what a model says a contract is worth. We never tell you what to trade.

What OptionWit is not

It is not a broker, a data feed, or a signal service. The prices are theoretical model estimates, not live quotes, and they will differ from your broker's screen because real markets add bid-ask spreads, dividends, early-exercise premium on American options, and implied volatility that moves with price and time. The methodology page spells out every assumption and limitation in plain terms.

Who runs it

OptionWit is an independent project, not affiliated with any broker or exchange. Questions, corrections, and feature requests are genuinely welcome, especially if you spot a number you think is wrong: the contact page has the details. If you find a math error, we want to hear about it more than anything else.

Teaching with it? OptionWit is free for classroom use, with an embeddable widget and a ready-made theta exercise on the for teachers page.

Open the free calculator → Enter your position and read its value across any future date and stock price. No signup, no account.