About the Covered Call Calculator
Writing a covered call means selling a call option against shares you own. You collect the premium up front, and in exchange you agree to sell your shares at the strike price if the stock is above it at expiration. This covered call calculator shows the two outcomes that matter most: your return if the shares are called away, and your return if the stock price is unchanged at expiry — both as a percentage of your net investment and annualised so you can compare trades of different lengths.
It is for income-focused investors and option sellers deciding which strike and expiry to write, or checking whether a premium is worth capping their upside. It also reports the break-even price (how far the stock can fall before you lose money), the percentage of downside protection the premium provides and the maximum profit per position. The chart compares the covered call’s profit at expiry with simply holding the stock.
Returns are measured against the net debit — the stock price minus the premium received — which is how a buy-write is usually evaluated. Commissions and taxes are not included. Enter any dividend you expect to receive before expiry to include it in the return.
With the default inputs, the return if called away is 13.4%. Change any value above to recalculate instantly.
How to use the covered call calculator
- 1Enter the price you pay for the stock (or its current price if you already own it).
- 2Enter the strike and premium of the call you plan to sell.
- 3Enter the days until expiration and the number of shares covered.
- 4Add any dividend due before expiry.
- 5Compare the return if called and if unchanged across different strikes.
Formula and method
The net investment (net debit) is the stock price minus the premium you receive. If the stock finishes above the strike, your shares are sold at the strike, so your profit is the strike minus the stock price, plus the premium and any dividends. If the stock is unchanged, you keep the shares and the premium; when the strike is below the current price the option is in the money, so you would still be assigned and give up the difference.
Both returns are divided by the net debit, then annualised with simple scaling (× 365 ÷ days) so trades with different expirations can be compared. The break-even price is the stock price minus premium and dividends, and downside protection is that cushion as a share of the stock price.
- S
- Stock price (your cost per share)
- K
- Call strike price
- P
- Premium received per share
- D
- Dividends received before expiration
Worked examples
Out-of-the-money call: $50 stock, $55 strike, $1.50 premium
Your net investment is $48.50 per share. If the stock stays at $50 you keep the $1.50 premium, a 3.09% return in 45 days (about 25% annualised). If it rises above $55 you also gain $5 on the shares: $6.50 ÷ $48.50 = 13.4%.
300 shares at $180, $185 strike, 30 days
Three contracts bring in $1,260 of premium. If unchanged, $4.20 ÷ $175.80 = 2.39% in a month; if called at $185, the total profit is $9.20 per share, or $2,760.
In-the-money call with a dividend
Selling the $37.50 call on a $40 stock gives up $2.50 of upside but collects $3.80 plus a $0.24 dividend. Because the call is in the money, the unchanged and called outcomes are the same: $1.54 ÷ $36.20 = 4.25%, with 10.1% downside protection.
Frequently asked questions
What is a covered call?+
A covered call is a strategy where you own at least 100 shares of a stock and sell one call option against them. You earn the premium immediately, but you must sell the shares at the strike price if the buyer exercises.
What is return if called vs return if unchanged?+
Return if called assumes the stock finishes above the strike and your shares are sold at the strike. Return if unchanged assumes the stock price does not move, so you keep the premium and, for out-of-the-money calls, your shares.
What is the risk of a covered call?+
Your upside is capped at the strike, but your downside is almost the same as owning the stock — the premium only cushions losses. If the stock falls sharply you can lose far more than the premium you collected.
How is the annualised return calculated?+
The calculator scales the period return by 365 ÷ days to expiration without compounding. It helps compare a 30-day trade with a 90-day one, but assumes you could repeat similar trades all year, which is not guaranteed.
Can I be assigned before expiration?+
Yes. American-style equity calls can be exercised at any time, most often the day before an ex-dividend date when the remaining time value is smaller than the dividend. If that happens you sell the shares at the strike early and do not receive the dividend, so the dividend-inclusive return here would not apply.
Should I choose an in-the-money or out-of-the-money strike?+
In-the-money calls give more downside protection and a more certain but smaller return. Out-of-the-money calls leave room for share-price gains and offer a higher return if called, with less protection.
Results are estimates for educational purposes and are not financial advice. Rates, fees and terms vary — confirm with your lender or a licensed advisor before making decisions.