Bull Put Spread Calculator

What Is a Bull Put Spread?

A bull put spread (also called a put credit spread) is a vertical spread where you sell a put at a higher strike and buy a put at a lower strike, both with the same expiration date. It's a moderately bullish strategy with limited risk and capped profit—you collect a credit upfront in exchange for taking on defined downside risk.

Key Characteristics

• Max Profit: Limited to the net credit you receive to enter the trade. Achieved when the stock closes at or above the short strike at expiration.
• Max Loss: (Spread width − net credit) × 100 × number of contracts. Occurs when the stock closes at or below the long strike at expiration.
• Breakeven: Short strike − net credit
• Outlook: Moderately bullish

How to Read the P/L Chart

The cyan line (T+0) shows your theoretical P/L at trade entry. Before expiration, the curve is smoother because both options still have time value. When the stock is above your breakeven, time decay works in your favor—you'll see T+0 sitting below the expiration line in this region. If the stock falls toward your long strike, time decay starts working against you because you need the long put's protection.

T+0 means "today plus 0 days," while T+30 would mean "today plus 30 days." It's a common convention for payoff diagrams that show multiple points in time.

The white line (Expiration) shows your profit or loss at expiration. If the stock is above the short strike, both puts expire worthless and you keep the full credit. Between the strikes, your profit shrinks as the short put gains intrinsic value. If the stock is below the long strike, your loss is capped—the long put gains value dollar-for-dollar with the short put. This payoff graph highlights the spread's defined risk and defined reward.

The relationship between the T+0 and Expiration P/L lines helps you visualize time decay. Wherever the T+0 line is below the expiration line, the position has positive theta and benefits from the passage of time. If the T+0 line is above the expiration line, the position has negative theta and will lose money as time passes.

Try hovering over the chart at various stock prices and compare the T+0 and Expiration P/L lines.

Using This Calculator

1. Stock Price: The price of the stock at trade entry
2. Short Strike: The higher strike, where you sell the put
3. Long Strike: The lower strike, where you buy the put
4. Net Credit: The premium you receive to enter the spread. To find your total potential profit, multiply the net credit by 100 and by the number of spreads. For example, a $1.50 net credit with 2 spreads is $1.50 × 100 × 2 = $300 max profit.
5. Days to Expiration: How much time is left until both options expire
6. Implied Volatility: The market's expectation of future stock price movements, as implied by the stock's option prices

What Is a Bull Put Spread? — Full strategy guide with examples

Bull Put Spread vs Short Put

Selling a put credit spread and a naked short put are both bullish strategies. The put spread just adds the long put at a lower strike to limit downside risk. The naked short put collects more premium and has pure, positive theta exposure, but has more downside risk and a higher margin requirement than a put credit spread.

When deciding between the two, I'll often default to selling a wide put spread to limit the downside risk. The exception is when I'm selling cash-secured puts.

Bull Put Spread vs Bull Call Spread

Both are bullish strategies with limited risk and capped profit. A bull call spread is a debit spread you pay to enter, while a bull put spread is a credit spread you receive premium to enter. At the same strikes and expiration, these positions have nearly identical max profit, max loss, and breakevens.

The difference comes down to which options are out-of-the-money. Traders typically sell OTM options for better liquidity and to avoid early assignment. If you expect the stock to stay above a certain price, sell an OTM put spread (bull put spread). If you expect a stronger move higher, buy an OTM call spread (bull call spread).

Bull Put Spread vs Bear Put Spread

Bull put spreads and bear put spreads are both vertical put spreads, but with opposite market outlooks. A bull put spread sells the higher-strike put and buys the lower-strike put for a credit—you profit if the stock stays above the short strike. A bear put spread does the opposite: buy the higher-strike put and sell the lower-strike put for a debit—you profit when the stock falls through the strikes.

A Note on Early Assignment

The short put in your spread can be assigned early, usually when it is deep ITM near expiration. If this happens, you will be long 100 shares, but your long put protects you. You can exercise your long put to sell the shares or close both legs separately. Either way, the spread structure protects you.

Bull Put Spreads in Multi-Leg Strategies

A bull put spread is half of an iron condor. Combine your bull put spread with a bear call spread above the stock price to create an iron condor—a neutral strategy that profits from range-bound price action. Read our iron condor options strategy guide for detailed examples and explanations.

Related Calculators

• Bull Call Spread Calculator — Debit spread alternative
• Cash Secured Put Calculator — Sell puts for income
• Bear Put Spread Calculator — Bearish counterpart
• All Vertical Spread Calculators — Bullish and bearish spreads