Double Calendar Spread at a glance
| Construction | Sell 1 put 2 strikes below the money in the front month, buy 1 put 2 strikes below the money in the next month, sell 1 call 2 strikes above the money in the front month, and buy 1 call 2 strikes above the money in the next month. |
|---|---|
| Outlook | Neutral |
| Volatility view | Wants rising IV |
| Max profit | Estimated value of the two back month options at front month expiration with the stock at one of the strikes, minus the net debit, times 100. |
| Max loss | Net debit paid, times 100. |
| Breakeven | The lower breakeven sits below the put strike and the upper breakeven above the call strike, at the prices where the estimated value of the back month options minus the intrinsic value of the front month options equals the net debit at front month expiration. |
| Experience level | Advanced |
| Also called | Double calendar, Strangle calendar |
How a double calendar spread works
A double calendar spread is two calendars side by side. On the downside you sell a front month put and buy a next month put at the same lower strike; on the upside you do the same with calls at a higher strike. You pay a net debit for both. Each short option is covered by a longer dated option at the same strike, so there are no naked shorts. Spreading the strikes apart widens the profit zone compared with a single at the money calendar.
Viewed at front month expiration, the payoff has two peaks, one at each strike, joined by a lower stretch between them, and it falls off beyond the strikes. If the stock finishes between the strikes, both short options expire worthless and you are left owning a next month strangle. Outside the breakevens the trade loses, with the full debit at risk on a very large move. Because the shape depends on the back month options' value at that moment, the calculator estimates max profit and breakevens with an American pricing model.
Before front expiration, the trade earns theta while the stock stays within the range, since both front month options decay faster than their back month partners. Vega is strongly positive with two long back month options, so rising implied volatility can lift the position even without a price change, while a broad volatility drop hurts. It also depends on the gap between months: the trade does best when front month volatility is high relative to the next month and that gap narrows.
Double Calendar Spread example with real numbers
With the stock at $100, implied volatility at 30%, a 4.1% risk free rate and no dividend, you would sell 1 95 put (32 days) at $1.43, buy 1 95 put (60 days) at $2.44, sell 1 105 call (32 days) at $1.78, buy 1 105 call (60 days) at $3.11. That is a net debit of $234. At the front month expiration, the model estimates a maximum profit of $173 and a maximum loss of $234, with breakevens at $93.00 and $108.81. The lognormal chance of profit is 62%.
These are theoretical American option prices from the Bjerksund and Stensland model, not live quotes. Load any ticker in the double calendar spread calculator above to run the same math on real market prices.
When to use a double calendar spread
- You expect the stock to stay within a range around the current price through front month expiration.
- You want a wider profit zone than a single at the money calendar offers.
- Implied volatility is low or moderate and you would welcome a rise.
- You want a range bound trade that is long volatility, unlike an iron condor.
Max profit, max loss and breakeven
Maximum profit
Estimated value of the two back month options at front month expiration with the stock at one of the strikes, minus the net debit, times 100. The peak depends on implied volatility at that time, so the calculator estimates it with an American pricing model.
Maximum loss
Net debit paid, times 100. The loss approaches this amount if the stock moves far beyond either strike, where the short and long options at that strike converge in value and the other pair is nearly worthless.
Breakeven
The lower breakeven sits below the put strike and the upper breakeven above the call strike, at the prices where the estimated value of the back month options minus the intrinsic value of the front month options equals the net debit at front month expiration. They depend on implied volatility, so the calculator estimates them with its American model.
Double Calendar Spread Greeks
- Delta: Delta is near zero at entry because the put and call calendars offset each other. It becomes negative as the stock rises past the call strike and positive as it falls past the put strike.
- Gamma: Gamma is negative, coming from the two short front month options, and it grows as front expiration approaches.
- Theta: Theta is positive across the range between the strikes, with the strongest decay near each strike.
- Vega: Vega is positive and larger than in a single calendar because you own two back month options. Rising implied volatility helps and falling volatility hurts.
See the live numbers for your position in the Greeks tab of the calculator, or explore a single option in the options Greeks calculator.
Early exercise and assignment risk
A double calendar has two short front month options, and each has its own early assignment trigger. The short call becomes a candidate if the stock rallies above the upper strike ahead of an ex dividend date, since American call holders often exercise the day before the ex date when the dividend exceeds the remaining time value. The short put becomes a candidate if the stock falls well below the lower strike and the put goes deep in the money with almost no time value, more so when interest rates are high.
In either case the back month option at the same strike covers you. A call assignment leaves you short 100 shares with a long next month call at that strike, and a put assignment leaves you long 100 shares with a long next month put at that strike, so risk stays defined. Exercising the long option to offset usually wastes its time value; trading the shares and keeping or selling the long option is generally better. The simpler approach is to close or roll the threatened side before it gets deep in the money.
The calculator's Early exercise risk tab flags short legs that are likely to be assigned. For a single option, use the early exercise calculator or read how early exercise and assignment work.
Pros and cons
Pros
- Wider profit range than a single calendar spread.
- Defined risk limited to the net debit, with every short option covered.
- Positive vega, so it can benefit from rising implied volatility while collecting theta.
- Each side can be adjusted or rolled on its own.
Cons
- Max profit and breakevens are model estimates, not fixed values.
- Four legs across two expirations raise commissions and slippage.
- A sharp move beyond either strike turns the position into a loss.
- A broad drop in implied volatility can hurt even when the stock stays in range.
How to manage a double calendar spread
- Close the trade before the front month's final days, when gamma risk on the short options is highest.
- If the stock moves past one strike, roll that calendar to a new strike or close it and keep the other side.
- After the front month options expire worthless, sell a new front month strangle against the back month options to collect more premium.
- Compare the double calendar with an iron condor in the calculator to see how differently they react to volatility changes.
Double Calendar Spread FAQ
What is a double calendar spread?
A double calendar spread is a put calendar at a lower strike combined with a call calendar at a higher strike, opened for a net debit. It profits when the stock stays near or between the two strikes until the front month options expire. Risk is limited to the debit paid.
Is a double calendar better than an iron condor?
A double calendar is not better than an iron condor, but it reacts to volatility the opposite way: a double calendar is long vega, while an iron condor is short vega. Both profit from a range bound stock. Traders often lean toward the double calendar when implied volatility is low and the iron condor when it is high.
How do I choose strikes for a double calendar?
Place the put strike near the bottom and the call strike near the top of the range you expect through front month expiration. Wider strikes widen the profit zone but lower the peak profit, while narrower strikes raise the peak but shrink the range. The calculator lets you compare these tradeoffs in the payoff chart.
What happens to a double calendar at front month expiration?
At front month expiration, any short option that is out of the money expires worthless, and you keep the back month options. If the stock finished between the strikes, you own a next month strangle, which you can sell or write new front month options against. An in the money short option should be closed before the close to avoid assignment.
Related strategies
Call Calendar Spread
A calendar spread sells a near term option and buys a longer dated option at the same strike, and it profits most when the stock sits near that strike as the short option expires.
Put Calendar Spread
A put calendar spread is a two leg debit spread that sells a front month put and buys a later dated put at the same strike, profiting most when the stock is near that strike as the short put expires.
Double Diagonal Spread
A double diagonal spread sells a front month strangle and buys a next month strangle with wider strikes, and it profits when the stock stays between the short strikes through front month expiration.
Iron Condor
An iron condor is a neutral, defined risk credit strategy that sells an out of the money put spread and an out of the money call spread on the same stock and expiration.
Educational tool, not financial advice. Calculations are theoretical and depend on your inputs; real fills, fees, early assignment and dividends can change results. Options involve risk and are not suitable for every investor.