Payoff Pro was born from a simple need: to see the risk and reward of an options strategy before putting it on — no spreadsheet, no login.
You enter the strikes and premiums of each leg and the calculator draws the payoff diagram at expiration, highlighting max profit, max loss and breakevens. All the math runs in your browser.
The expiration result is computed from the intrinsic value of each option plus the net credit or debit. Max profit, max loss and breakevens are derived straight from the curve, with no formulas that break on asymmetric cases. The Calendar Spread uses Black-Scholes with constant implied volatility.
The charts show the result at expiration. They don't model profit or loss before it, which would involve the greeks and volatility. The tool is educational and doesn't replace your own analysis.