PutFinder › Cash-secured put calculator
Cash-secured put calculator
A free calculator for cash-secured puts. Enter a strike, premium, current price, days to expiration and number of contracts — it returns the capital secured, static return, annualized yield, breakeven and downside buffer. Every figure is arithmetic on the numbers you type.
What these figures are. Every output is plain arithmetic on the numbers you entered — no live market data, no ranking, no recommendation. The calculator does not estimate a probability of profit or tell you what to trade. It is descriptive, not investment advice.
$100 strike, $2 premium, $105 underlying, 30 days, 1 contract gives: capital secured $10,000.00, premium collected $200.00, static return 2.00%, annualized yield 24.33%, breakeven $98.00, downside buffer 4.76%. The values loaded above match those numbers.
How each figure is calculated
These are the standard cash-secured put math. Each is reproducible from the five inputs above — nothing is estimated or forecast. Writing calls instead? Use the covered call calculator — the other leg of the wheel. For how the two strategies compare, see cash-secured put vs covered call. For how PutFinder combines factors like these into a single relative rank, see the scoring methodology; for the screening process end to end, see how a CSP screener works. See all free tools on the tools hub.
- Capital secured = strike × 100 × contracts
- The cash set aside to buy the shares at the strike if assigned. One contract covers 100 shares, so a $100 strike secures $10,000 per contract.
- Premium collected = premium × 100 × contracts
- The cash received for selling the put, in dollars. The per-share premium times 100 shares per contract times the number of contracts.
- Static return = premium ÷ strike
- The premium as a fraction of the strike, over the life of one contract. A unitless ratio — the per-share amounts cancel, so there is no ×100 contract multiplier here. Arithmetic on the premium, not a return prediction.
- Annualized yield = (premium ÷ strike) × (365 ÷ DTE)
- The static return scaled to a one-year rate by the days to expiration. Also a unitless ratio — no contract ×100. It describes the current premium on a per-year footing so contracts of different lengths compare on the same basis; it is not an expected, projected, or compounded return.
- Breakeven = strike − premium
- The per-share price at which the position turns from a paper gain to a paper loss at expiration — the strike reduced by the premium already received.
- Downside buffer = (current price − strike) ÷ current price
- How far the underlying can fall from today's price, as a percentage, before it reaches the strike. A larger buffer means more room before assignment comes into play. Descriptive, not a probability.
References
- The Options Industry Council (OIC) — options basics, assignment, and the cash-secured put: optionseducation.org.
- Cboe S&P 500 PutWrite Index (PUT) — a benchmark for systematically selling cash-secured puts: cboe.com/us/indices/dashboard/PUT.
- Cboe Options Institute — education on options mechanics and terminology: cboe.com/optionsinstitute.
Common questions
How do you calculate the return on a cash-secured put?
Divide the premium per share by the strike to get the static return, then multiply by 365/DTE to annualize it. A $100 strike collecting $2 over 30 days gives a static return of 2.00% and an annualized yield of 24.33%. Both are arithmetic descriptions of the premium relative to the capital secured — not an expected or guaranteed return.
How much capital does a cash-secured put require?
One standard contract covers 100 shares, so the cash tied up is strike × 100 × contracts. A single $100-strike contract secures $10,000 — the cash set aside to buy the shares at the strike if the put is assigned.
What is the breakeven on a cash-secured put?
The breakeven is the strike minus the premium per share. Sell a $100-strike put for $2 and the breakeven is $98 — the price at which the position turns from a paper gain to a paper loss at expiration. It describes the entry math, not a forecast of where the stock goes.
Is this cash-secured put calculator investment advice?
No. It runs pure arithmetic on the numbers you type — no live data, no ranking, no recommendation. Annualized yield is arithmetic on the premium you entered, not a return prediction, and it does not estimate a probability of profit. It is a descriptive tool, not investment advice.
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