BASIC · EXPIRATION PAYOFF

Long Put Calculator

See how a purchased put responds to a fall in the stock price.

Your position

Illustrative starting values · USD

Use one stock or ETF and the same expiration for every option leg. Premiums are per share.

Stock quantities are shares. Option quantities are contracts. Enter the total fees for the entire position once.

How to use the long put calculator

Buy a put. Enter the strike and premium paid. The lowest modeled stock price is zero.

Understanding the payoff

Breakeven = strike − premium. Maximum loss is the premium paid. Maximum profit is (strike − premium) × shares represented, reached if the stock falls to zero.

These formulas describe the standard strategy before fees. The results above include the total fees entered and are calculated from your actual legs.

Worked example

A $100 put bought for $5 breaks even at $95. At $90 at expiration, one standard contract produces a $500 profit before fees.

Read the strategy guide →

Assumptions and limits

This is an expiration payoff estimate, not a live option quote or a prediction. It assumes all option legs expire together on one stock or ETF, the stock price cannot be negative, and options settle at intrinsic value. The default multiplier is 100 shares per contract; adjust it for the contract being modeled. Early assignment, exercise decisions, dividends, interest, taxes, and slippage can change realized results. Cash requirements and broker margin are separate from maximum loss. Different expirations, futures options, and adjusted contracts with non-cash deliverables are not supported.

Method: add each leg’s intrinsic value at expiration, subtract its entry cost with the correct buy/sell sign, and subtract total fees. See Cboe’s worked spread example on Fidelity for a reference calculation.