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OptionsMath

Put Option Profit/Loss Calculator

Profit or loss equals the maximum of strike price minus stock price or zero, times 100 shares times number of contracts, minus premium times 100 shares times number of contracts.

Expiration scenarios

Solution

Enter values to calculate

Educational estimate only, not financial advice. Results exclude commissions, taxes, slippage, dividends, assignment risk, margin, and broker-specific rules. Verify before trading options.

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Put Option Formula

K

Strike price of the put option.

S

Stock price at expiration.

P

Premium paid per share for the put.

N

Number of option contracts. One listed equity contract usually controls 100 shares.

  • Break-even price for a long put = strike price - premium per share.
  • Maximum loss is limited to the premium paid.
  • Maximum gain is capped because the stock price cannot fall below zero.

Worked Examples

Use these example trades to see how expiration payoff changes across different options setups.

PORTFOLIO HEDGE

How do you estimate a protective put on an index ETF?

A portfolio manager buys 2 put contracts on an index ETF with a $450 strike and an $8.50 premium to protect against a sharp correction. The ETF closes at $410 on expiration day.

  • Premium cost = $8.50 × 100 × 2 = $1,700.
  • Intrinsic value = ($450 - $410) × 100 × 2 = $8,000.
  • Net profit = $8,000 - $1,700 = $6,300.
  • Break-even = $450 - $8.50 = $441.50.

Result: the hedge generates a $6,300.00 profit, with break-even at $441.50.

A real hedge also has to be judged against losses in the underlying stock or ETF, not only by the standalone option payoff.

BEARISH RETAIL TRADE

How do you price a directional bearish put?

A trader buys 1 put with a $90 strike and a $3.40 premium on a retail stock they expect to weaken after guidance. The stock closes at $78 at expiration.

  • Premium cost = $3.40 × 100 × 1 = $340.
  • Intrinsic value = ($90 - $78) × 100 × 1 = $1,200.
  • Net profit = $1,200 - $340 = $860.
  • Break-even = $90 - $3.40 = $86.60.

Result: the long put earns $860.00, and the trade needed the stock below $86.60 to make money.

This is expiration payoff only; before expiration the option value can change because of volatility and time decay even if the stock does not move.

INSURANCE THAT EXPIRES

What if the protective put is never needed?

An investor buys 1 put on a utility stock with a $300 strike and a $6.10 premium as downside insurance. The stock closes at $315 on expiration day.

  • Premium cost = $6.10 × 100 × 1 = $610.
  • Intrinsic value = max($300 - $315, 0) × 100 = $0.
  • Net profit/loss = $0 - $610 = -$610.
  • Break-even = $300 - $6.10 = $293.90.

Result: the put expires worthless, so the option buyer loses the full $610.00 premium.

That outcome can still be acceptable when the put was purchased as insurance and the investor benefited from the stock staying strong.

How It Works

A long put option gives you the right to sell 100 shares at the strike price before expiration. You pay a premium for that protection or bearish exposure. At expiration, the put gains intrinsic value when the stock finishes below the strike price. Profit comes from that downside move being large enough to cover the premium paid.

Example Problem

You buy 1 put option contract with a $100 strike for a $5 premium per share. The stock closes at $85 on expiration day. What is the profit, break-even price, and maximum gain?

  1. Identify the known values: strike price K = $100, premium P = $5 per share, expiration stock price S = $85, and contracts N = 1.
  2. Write the long put expiration formula: Profit/Loss = max(K - S, 0) × 100 × N - P × 100 × N.
  3. Calculate the premium paid: $5 × 100 × 1 = $500 total contract cost.
  4. Calculate intrinsic value at expiration: max($100 - $85, 0) × 100 × 1 = $1,500.
  5. Subtract the premium cost from intrinsic value: $1,500 - $500 = $1,000 net profit.
  6. Compute break-even separately: $100 - $5 = $95, and note that the maximum gain would occur only if the stock fell all the way to $0.

A long put has limited downside risk for the option buyer, but its maximum gain is capped because a stock price cannot fall below zero.

Key Concepts

Strike price is the price you can sell the stock for if you exercise the put. Premium is the amount paid per share for the option, and each contract usually controls 100 shares. Break-even for a long put is strike minus premium. Maximum loss is the premium paid. Maximum gain is capped because the stock cannot fall below zero, so the best possible outcome is roughly strike minus premium, multiplied by 100 shares per contract.

Applications

  • Expressing a bearish view while keeping risk limited to the premium paid.
  • Hedging a long stock or ETF position against a downside move.
  • Testing protective put scenarios before earnings or macro events.
  • Comparing how contract count changes defined-risk downside protection.

Common Mistakes

  • Mixing up intrinsic value with total profit and forgetting to subtract the premium paid.
  • Forgetting that each listed equity option contract usually represents 100 shares.
  • Assuming maximum gain is unlimited even though a stock price cannot go below zero.
  • Treating expiration payoff as a live option pricing model before expiration.

Frequently Asked Questions

What do I need to know before buying a put option?

A long put is useful when you expect a stock to fall or when you want downside insurance on a long stock position. Your risk is limited to the premium paid, but the stock still has to fall far enough to move below break-even before the position becomes profitable.

How do you write the long put payoff formula?

At expiration, long put profit or loss is max(K - S, 0) × 100 × contracts - premium × 100 × contracts. The max() term is there because the put cannot have negative intrinsic value; it simply expires worthless when the stock finishes at or above the strike.

When is a long put trade actually profitable?

A long put becomes profitable when the stock finishes below the break-even price, not just below the strike. Break-even equals strike price minus premium per share.

What happens if the stock finishes above the strike price?

The option expires worthless because selling at the strike has no advantage over selling at the market price. In that case, the long put buyer loses the premium paid, and that premium is the maximum loss.

How is the break-even price for a put calculated?

Break-even equals strike price minus premium per share. If you buy a $100 put for $5, the stock must close below $95 at expiration for the position to show a net profit.

Why does a long put have capped upside?

A stock cannot fall below zero, so the most intrinsic value a long put can gain is the full strike price. That is why maximum gain is limited to (strike - premium) × 100 × contracts.

How do protective puts differ from outright bearish puts?

A protective put is paired with a long stock position to cap downside risk. An outright bearish put is purchased without owning the stock and is used to speculate on a decline.

How do more contracts affect a put position?

Each additional contract scales the payoff linearly. Double the contracts and you double the premium paid, the maximum loss, the maximum gain, and the dollar profit or loss at every stock price.

Should I use this calculator for expiration payoff or option pricing before expiration?

Use it for expiration payoff only. It does not include time value, implied volatility, early exercise choices, or Greeks, so it is not a substitute for a live options pricing model.

How is a put option different from shorting stock?

Shorting stock creates theoretically unlimited risk if the price rises. Buying a put limits risk to the premium paid while still giving downside exposure if the stock falls.

Reference: Options Clearing Corporation, Characteristics and Risks of Standardized Options (ODD), long put payoff and protective put concepts.

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