Calculator Inputs
Use one strike for both options. This matches a standard long straddle.
Formula Used
max(Underlying Price at Expiry − Strike Price, 0)
max(Strike Price − Underlying Price at Expiry, 0)
Call intrinsic + Put intrinsic − Call premium − Put premium
Net profit per share × Contract size × Number of contracts
Lower break-even = Strike price − Total premium
Upper break-even = Strike price + Total premium
A long straddle buys one call and one put at the same strike. The trade pays a debit first. It then profits from large movement in either direction. If the lower break-even becomes negative, there is no practical downside break-even in the real market.
How to Use This Calculator
- Enter the current spot price for context.
- Enter one strike price for both options.
- Fill in the call and put premiums paid.
- Set the contract count and contract size.
- Choose the minimum, maximum, and step for the payoff range.
- Enter a target expiry price to test one scenario.
- Submit the form to view the summary, graph, and payoff table.
- Use CSV or PDF export for reporting or review.
Example Data Table
Example values below use strike 100, call premium 6, put premium 5, one contract, and contract size 100.
| Underlying Price | Call Intrinsic | Put Intrinsic | Net Profit Per Share | Total Profit or Loss |
|---|---|---|---|---|
| 80.00 | 0.00 | 20.00 | 9.00 | 900.00 |
| 89.00 | 0.00 | 11.00 | 0.00 | 0.00 |
| 100.00 | 0.00 | 0.00 | -11.00 | -1100.00 |
| 111.00 | 11.00 | 0.00 | 0.00 | 0.00 |
| 120.00 | 20.00 | 0.00 | 9.00 | 900.00 |
FAQs
1. What is a long straddle?
A long straddle buys one call and one put with the same strike and expiry. It seeks profit from strong price movement either upward or downward after paying both premiums.
2. When does the strategy lose the most?
The maximum loss happens when the underlying expires exactly at the strike. Both options lose all intrinsic value, so the trader loses the total premium paid.
3. Why are there two break-even prices?
The trader can profit on either side of the strike. One break-even sits below the strike, while the other sits above it by the total premium amount.
4. Can the downside profit be unlimited?
No. A stock price cannot fall below zero. That makes downside profit limited, while upside profit remains open-ended if the price rises sharply.
5. What does contract size change?
Contract size scales the per-share payoff into total money. A standard equity option often controls 100 shares, so every net point becomes 100 currency units per contract.
6. What if the lower break-even is negative?
If total premium exceeds the strike, the theoretical lower break-even becomes negative. In practice, that means no realistic downside break-even exists because prices cannot go below zero.
7. Does this calculator include commissions and taxes?
No. This version focuses on option payoff math. Add brokerage fees, taxes, slippage, and assignment effects separately if you need a complete trading cost estimate.
8. How should I read the payoff graph?
The graph shows total profit or loss at different expiry prices. The center dip reflects the premium cost, and the rising edges show profit from large moves away from the strike.