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Cash-secured put calculator
Calculate premium after fees, cash required, expiration breakeven and downside before comparing a cash-secured put candidate.
Use your own quote or start with the fictional example below. Inputs stay in this browser; this tool does not fetch quotes or place trades.
Compare the return and the commitment
USD · Standard 100-share equity option contracts · Held to expiration
Your expiration scenario
1 contract, $50 strike, $1 premium/share, 30 days, $0 total fees.
- Gross cash obligation
- $5,000.00
- Gross premium
- $100.00
- Premium after fees / maximum P&L
- $100.00
- Expiration breakeven
- $49.00 per share
- Net premium / gross collateral
- 2.00%
- Simple annualized premium yield
- 24.33%
- Loss if the stock falls to zero
- $4,900.00
- At an expiration stock price of $40.00 (100 shares):
- -$900.00
Annualized premium yield is a comparison metric, not a forecast. It does not assume you can repeatedly earn this premium. Assignment requires buying the shares even if their value has fallen substantially.
How the calculator works
- Shares: contracts × 100.
- Gross cash obligation: strike × shares. This tool does not deduct received premium from the denominator; your broker’s buying-power requirement may differ.
- Net premium: premium per share × shares − total fees.
- Breakeven: strike − net premium ÷ shares. If fees exceed premium, this expiration model has no profitable stock-price outcome and no breakeven.
- Expiration profit/loss: net premium − max(strike − expiration stock price, 0) × shares.
- Simple annualized yield: net premium ÷ gross cash obligation × 365 ÷ days × 100%.
The default example collects $100 and commits $5,000. A $40 expiration stock price produces a $900 loss after the premium. At or above the $50 strike, modeled P&L is $100. With $2 total fees, those outcomes become −$902 and $98, and breakeven becomes $49.02.
These are expiration payoffs, not current option valuations. Early assignment, closing or rolling, stock movements after expiration, adjusted contracts, taxes and interest are outside this model. Exercise decisions near the strike can differ from the simplified payoff assumption.
Strategy reference: Options Industry Council: cash-secured puts. Educational calculations only; not investment advice.
Cash-secured put calculator questions
Is premium the same as profit?
No. Premium is received when selling the put. Fees and the downside obligation can make the final result negative, as the default scenario shows.
Can I calculate several contracts?
Yes. Enter a whole number of standard contracts and the total fees for the entire position. Cash obligation and downside scale with the share count.
Does this calculate the probability of assignment?
No. It shows outcomes at a stock price you choose. It does not estimate probability, recommend a strike or predict prices.
Put the numbers alongside your research
Read the CSP screener walkthrough, learn the wheel strategy, or explore the options income guide.
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