Estimate premium income and expiration outcomes for fully covered standard 100-share equity calls. Compare current-price returns and original-cost profit; fees, dividends and taxes are excluded.
Covered Call Return Formulas
For a stock unchanged at expiration, the return includes any in-the-money call cap. If the strike is at or above the current price, this reduces to premium divided by current price:
RIF = (Prem + min(S, K) - S) / S * 100
If the stock is called away at the strike, the return adds the capital gain up to the strike:
RIA = (Prem + (K - S)) / S * 100
Variables:
- RIF is the expiration return if the stock stays at S (%); an in-the-money call limits stock proceeds to K
- RIA is the return if assigned (%) – the total return if shares are called away at the strike
- Prem is the premium received per share ($)
- S is the current stock price ($)
- K is the call strike price ($)
Enter original share cost, current price, strike, premium per share and whole days to expiration. Contracts must be whole; blank means one standard contract backed by 100 owned shares. Premium income is separate from profit. Expiration P&L = premium + min(expiration price, strike) − stock basis. A breakeven exists at basis minus premium only when that value is between zero and the strike; otherwise the modeled position has no single nonnegative breakeven. Annualized values in Calculation details multiply period returns by 365/days; they are not forecasts.
Covered Call Outcomes at Expiration
For 100 shares at $50, selling a $52.50 call for $1.20: how the position performs at different expiration prices.
| Stock at expiration | Outcome | Total P&L vs $50 |
|---|---|---|
| $46.00 | Call expires; keep shares + premium | -$280 (loss cushioned by $120) |
| $48.80 | Breakeven after premium | $0 |
| $50.00 | Call expires; keep shares + premium | +$120 (2.4% in the period) |
| $52.50 | At the strike – maximum profit | +$370 (7.4%) |
| $56.00 | Assigned at $52.50; upside capped | +$370 (gave up $350 of upside) |
The strategy trades unlimited upside for immediate income: every outcome below the strike is improved by the premium, and every outcome above it is capped at the same maximum.
Example Problems
Example 1: Monthly income trade.
You own 100 shares trading at $50.00, bought at $48.00, and sell a 30-day $52.50 call for $1.20.
Premium income = $120. Return if flat = 1.20 / 50 = 2.4%, which annualizes to 2.4 * 365/30 = 29.2%. Return if assigned = (1.20 + 2.50) / 50 = 7.4% (90% annualized). Max profit vs your $48 cost = (1.20 + 4.50) * 100 = $570.
Example 2: Downside protection.
Same position: the premium is a 1.20 / 50 = 2.4% buffer relative to current stock value. Expiration breakeven is $48.80 versus the current $50 price, or $46.80 versus the original $48 cost. It does not protect against a large decline.
Frequently Asked Questions
What happens if the stock rises above the strike?
The expiration model caps stock proceeds at the strike. Actual exercise and assignment depend on the contract and broker, and American-style calls can be assigned early. Rolling requires another trade, can cost money, and does not guarantee keeping the shares.
Which strike should I sell?
Strike selection changes the balance between premium, capped upside and assignment risk. This calculator does not recommend a strike or estimate assignment probability. Delta is not a guarantee of an outcome.
Is a covered call risky?
Stock losses can remain substantial. Under the expiration model, stock becoming worthless produces P&L of (premium − stock basis) × shares. Premium cushions this loss, while the call caps upside; actual returns also depend on costs, dividends, taxes and assignment.
