Theo Chen

Founder, The Options Bench

I have traded options as a retail trader out of Asia for over a decade - through a few full market cycles, a handful of painful assignments, and more rolled positions than I would care to count. My day-to-day is income strategies: covered calls, cash-secured puts, the wheel, and the occasional spread, managed around days-to-expiration and the Greeks rather than gut feel.

The Options Bench started from a simple frustration. Most options calculators are built to rank in search engines, not to answer the question a trader actually has before placing an order. They gloss over the edge cases - in-the-money covered calls, zero-DTE math, what your cost basis really becomes after assignment. So I build the tools I wanted myself: small, fast, free, and correct on the awkward cases.

Everything here is built to be checked. The exact formula behind every calculator is published on How We Calculate, and each one is pinned down by an automated test suite - more than 500 assertions that must pass before any change reaches the live site, with the awkward edge cases (in-the-money positions, zero-DTE math, post-assignment cost basis) covered on purpose. If a number ever looks wrong, tell me and I will check it and fix it.

I am not a financial advisor, and nothing here is advice. I am a trader who codes, sharing the same math I use to size up my own positions.

Calculators built

  • Covered Call Calculator Model max profit, breakeven, annualized return, downside protection and the payoff diagram for a covered call.
  • Cash-Secured Put Calculator Return on capital, effective cost basis if assigned, and breakeven for a cash-secured put.
  • Wheel Strategy Calculator Track premium, cost basis and P&L across every cycle of the wheel — puts, assignment and called-away events.
  • Rolling Decision Calculator Repair an in-the-money short put: net credit, new breakeven, and which of the three roll-repair stages your roll is.
  • Poor Man's Covered Call Calculator Run a covered call on a LEAPS instead of 100 shares: net debit, max profit, breakeven, return on debit and an annualized income yield.
  • Bull Put Spread Calculator Sell a put credit spread with defined risk: net credit, max profit, max loss, breakeven, return on risk and the payoff diagram.
  • Call Spread Calculator Bull call (debit) or bear call (credit) vertical: net debit/credit, max profit, max loss, breakeven, return on risk and the payoff diagram.
  • Calendar Spread Calculator Same-strike call or put calendar: net debit, estimated near-expiry max profit, max loss, both breakevens and return on debit, with the far leg priced by Black-Scholes.
  • Iron Condor Calculator Both credit spreads at once: net credit, max profit, max loss, both breakevens, profit-zone width and annualized return on risk.
  • Iron Butterfly Calculator Sell the ATM straddle inside protective wings: net credit, max profit, max loss, both breakevens, profit-zone width and return on risk.
  • Butterfly Spread Calculator Long 1-2-1 call or put butterfly: net debit, max profit at the body, max loss, both breakevens, profit-zone width and return on risk.
  • Straddle & Strangle Calculator Long straddle or strangle: buy a call and a put for a move either way — net debit, max loss, both breakevens and the percentage move needed to profit.
  • Long Call & Long Put Calculator Buy a single call or put with defined risk: net debit, max loss, breakeven, max profit and the percentage move the stock needs to reach profit.
  • Diagonal Spread Calculator Call or put diagonal — a calendar with two strikes: estimated near-expiry max profit, net debit (max loss), breakeven and return on debit, far leg priced by Black-Scholes.
  • Protective Put Calculator Insure long stock with a put: protected floor, maximum loss, breakeven, the cost of protection and its annualized rate.
  • Collar Calculator Protect a stock holding with a put and finance it with a call: net cost, protected floor, capped ceiling, max loss and max gain.
  • Payoff Diagram Builder Plot the expiration P&L of any multi-leg options position — max profit, max loss and breakevens.
  • IV Rank & IV Percentile Calculator See where implied volatility sits in its 52-week range — and whether it is a rich or poor time to sell premium.
  • Expected Move Calculator Turn implied volatility into a 1SD and 2SD price range by expiration — the move the options market is pricing in.
  • Black-Scholes Calculator Price a European call and put from the five Black-Scholes inputs — and see the full set of Greeks: delta, gamma, theta, vega and rho.
  • Options Probability Calculator Turn implied volatility into the odds a stock finishes past a target, expires short of it, or ever touches it before expiration.
  • Strategy Finder Not sure where to start? Answer four questions and get a matched strategy — with a link straight to its calculator.
  • Options Expiration Calendar Upcoming US options expiration dates — every monthly third Friday and weekly expiry, with the days to each, computed live in your browser.
  • Kelly Criterion Position Sizing Size positions by your edge: Full, Half and Quarter Kelly as a percent of your account and in dollars, plus a sensitivity table.
  • Kelly Criterion Simulator Watch Full, Half and Quarter Kelly compound an account trade by trade on the same random run — equity curve, ending balance and max drawdown.

Published guides

Reach the desk at /contact/ or read more about the site on the about page.

Educational content only. Nothing on The Options Bench is financial advice.