Calculator Inputs
Example Data Table
| Underlying | Long Strike | Short Strike | Long Premium | Short Premium | Contracts | Fees | Breakeven | Max Profit | Max Loss |
|---|---|---|---|---|---|---|---|---|---|
| $102.00 | $105.00 | $95.00 | $6.80 | $2.10 | 3 | $4.50 | $100.2850 | $1,585.50 | $1,414.50 |
Formula Used
This calculator treats the spread as a debit trade using one long higher-strike put and one short lower-strike put with the same expiration date.
How to Use This Calculator
- Enter the stock price when planning the trade.
- Input the higher strike for the long put.
- Input the lower strike for the short put.
- Add the premiums paid and received per share.
- Set contracts, multiplier, and your expected total fees.
- Enter a target expiry stock price for one specific scenario.
- Choose a minimum price, maximum price, and step for the payoff table.
- Press Calculate Spread to show the results above the form.
- Use the CSV or PDF buttons to export the calculated scenario data.
Frequently Asked Questions
1. What is a bear put spread?
A bear put spread is a bearish options strategy. You buy a higher-strike put and sell a lower-strike put with the same expiration. It limits both profit and loss compared with buying a naked put.
2. When does maximum profit occur?
Maximum profit happens when the stock finishes at or below the short put strike at expiration. At that point, the spread reaches its full strike-width value, minus the initial debit and total trading fees.
3. Why is the long strike higher?
The long put must have the higher strike so the position gains value as the stock falls. The short lower-strike put helps offset cost, creating a cheaper bearish trade with capped upside and downside.
4. What does the breakeven price mean?
Breakeven is the stock price at expiration where profit becomes zero after the debit and fees. Below that point, the spread profits. Above it, the position loses money, subject to the maximum loss limit.
5. Why include commissions and fees?
Fees reduce net performance. They slightly increase effective cost, lower maximum profit, and move breakeven. Including them makes scenario analysis more realistic, especially for smaller positions or frequent options traders.
6. Does the calculator estimate values before expiration?
No. This version focuses on expiration outcomes, not theoretical values before expiry. It does not model time decay, implied volatility changes, or early assignment probabilities before the options expire.
7. What does ROI on risk show?
ROI on risk compares projected profit with maximum capital at risk. It helps you judge whether the reward justifies the debit paid, especially when comparing several bearish spreads with different widths and costs.
8. Can I use nonstandard contract multipliers?
Yes. The multiplier input supports standard equity contracts or adjusted contract sizes. That makes the calculator useful for mini options, corporate action adjustments, or educational examples using custom share equivalents.