Diagonal Spread Calculator
Model your diagonal spread before you place it. Enter your long and short strikes and premiums to instantly see max profit, max loss, breakeven, and a full P&L diagram.
How to Use This Calculator
Four inputs and the calculator handles the rest. Results update instantly as you type.
Pull current market data (optional)
Type a ticker like AAPL and click Get Price. The calculator fills in the current stock price, dividend yield, and the risk-free rate from the 13-week T-bill, then loads the option chain so you can pick actual strikes and premiums.
Set up your diagonal spread legs
The diagonal spread legs are preloaded for you. Pick each strike, expiration, and premium straight from the option chain, or type your own numbers. The calculator works out implied volatility from the premium you enter, and you can still edit it.
Calculate and read the results
Click Calculate P&L to see max profit, max loss, breakeven, return on risk, and probability of profit, plus position Greeks: delta, gamma, theta, vega, and rho.
Stress test before you trade
Drag the view-date slider to see your P&L curve on any day before expiration, shift implied volatility up or down 50 points, and scan the price-by-date P&L table to see how the trade behaves across scenarios.
This diagonal spread calculator prices each leg with your choice of an American-style binomial model (the default for US equity options) or European Black-Scholes-Merton, and accounts for dividend yield. You can set a per-contract commission, copy a shareable link to your exact setup, download the chart as a PNG, and switch to dark mode.
Understanding the Diagonal Spread
Key numbers every diagonal spread trader needs to know before entering the position.
The diagonal spread earns its name from the way it appears on an options chain: moving diagonally across both the strike column and the expiration column. By combining different strikes and different expirations, the strategy layers a directional view on top of a time decay structure. The short front-month option decays faster than the long back-month option, giving you a built-in theta advantage while you wait for the stock to move in your favor.
For a bullish call diagonal, you want the stock to drift higher and close near or above the short call strike at front-month expiration. If it does, the short call expires worthless, you capture the full premium, and the long back-month call has appreciated in value. You can then sell another short-term call against the remaining long leg, repeating the cycle to reduce your net debit further each expiration.
One important check before entering any diagonal: confirm that the spread width (short strike minus long strike) is greater than the net debit. If the spread width is less than the net debit, the maximum profit would be negative, making the trade not worth taking at those prices.
Diagonal Spread Example Trade
XYZ is trading at $100. You buy a 60-day $95 call for $8.00 and sell a 30-day $105 call for $2.00.
Explore other options strategy calculators
Each strategy has its own dedicated calculator with a full P&L breakdown, worked example, and FAQ.
Free download
Download the free options trading journal
This calculator shows your diagonal spread setup before you enter. Log every leg, every roll, and every close to see your actual net P&L. Enter your email to get the free options trading journal template (Excel and Google Sheets).
- Free trading journal template (Excel and Google Sheets)
- Track win rate, average P&L, and trade history by strategy
- Works with any broker. No app required.
