Say what the contract is and which side of it you are on — a call or a put, bought or sold — then type the contracts, the premium per share, the strike, the contract multiplier and the stock price at expiration you want to look at. The page works out what the contracts cover, the money paid or received to open the position, what one share is worth at that price, what the position is worth, the profit or loss, the return, the breakeven, and eleven stock prices at expiration in a row with the result at each one. Every line of the arithmetic is printed below with your own figures. Nothing is looked up: there is no option chain and no live quote behind this page, so every number is one you typed. The contract is valued at expiration only.
The contract, and your side of it
The option — a call or a putA call is worth something at expiration only if the share price finishes above the strike; a put only if it finishes below. The page writes that as max(0, …) so you can see the arithmetic rather than a rule of thumb.
Your side of the contract — do you buy it or sell itBuying and selling the same contract give results of the same size with opposite signs. Both sides share the one breakeven price, read from either side of it.
The numbers
Number of contracts — how many you hold or writeWhole contracts in almost every case; the box takes decimals, but a fraction of a contract is not something a broker will fill.
Premium per share — what one share of the option costs, not the whole contractOption prices are quoted per share and multiplied by the contract multiplier when they are paid. Type the quote you have in front of you — the page multiplies it, it does not look it up.
Strike price — the price written into the contractThe per-share price the contract is written against. Everything on this page turns on this one number and the price at expiration.
Contract multiplier — the shares one contract covers100 for most US listed stock options, and that is the number this box starts with. It is editable on purpose: a contract adjusted for a split, a merger or a special dividend can cover a different number of shares, and non-US contracts often do. Use the multiplier written in the specifications of the contract you actually hold — that document, not this box, is what governs.
The price you want to look at
Stock price at expiration — a price you typeThe share price you want to look at on expiration day. There is no quote feed here, so this is your figure, not a fetched one. Type 0 to see the arithmetic for a share price of nothing.
Target profit or loss — optional, for the reverseFill this in and the page turns the arithmetic around: the stock price at expiration that produces that profit or loss. A loss is a negative number. Leave it empty and the page stops at the profit or loss above.
Shares the contracts cover — contracts × multiplier—
Money paid to open—
Value of one share at expiration — the max(0, …) line—
Value of the position at expiration—
Profit or loss—
Profit or loss — as a percentage of the money paid—
Breakeven at expiration — strike ± premium per share—
Stock price at expiration for that — the reverse—
Where that sits — against the strike—
Stock at expiration
Value of the contract
Profit or loss
How the profit and loss is worked out
Six numbers come from you: the contracts, the premium per share, the strike, the multiplier, the stock price at expiration, and the side of the contract you are on. Everything else is derived from those.
Shares the contracts cover = contracts × contract multiplier
Money paid (buyer) or received (seller) = premium per share × contract multiplier × contracts
Value of one share at expiration = max(0, stock at expiration − strike) for a call, max(0, strike − stock at expiration) for a put
Value of the position at expiration = value of one share × contract multiplier × contracts
Profit or loss, buyer = value at expiration − money paid
Profit or loss, seller = money received − value at expiration
Breakeven at expiration = strike + premium per share for a call, strike − premium per share for a put
P/L = (value of one share at expiration − premium per share × the side's sign) × contract multiplier × contracts
Worked example, buyer's side: two call contracts at a premium of 3.0000 per share, strike 100.0000, multiplier 100.0000, with the share price at 110.0000 on expiration day. The contracts cover 2.0000 × 100.0000 = 200.0000 shares. Money paid to open = 3.0000 × 100.0000 × 2.0000 = 600.00. One share is worth max(0, 110.0000 − 100.0000) = 10.0000, so the position is worth 10.0000 × 100.0000 × 2.0000 = 2,000.00. Profit or loss = 2,000.00 − 600.00 = 1,400.00, which is 233.33% of the money paid. The breakeven is 100.0000 + 3.0000 = 103.0000 per share.
Same contract from the seller's side: one contract at the same 3.0000 premium and the same strike, share price again 110.0000. Money received = 300.00, the position is worth 10.0000 × 100.0000 = 1,000.00, and the seller's profit or loss is 300.00 − 1,000.00 = −700.00. The breakeven is the same 103.0000 per share, reached from the other direction: the seller is ahead while the share price finishes below it.
Rounding: every figure on this page is rounded down, never up — the same rule as the rest of the site. Premiums, strikes and stock prices are shown to four decimals and money to two, so the figure you read is never larger than the one that was computed. Each line of the arithmetic is printed under the results using the figures shown above it, so the whole chain can be checked by hand.
The two sides of the same contract
An option is a contract, so there are always two sides, and they are not mirror images in every respect. The arithmetic says which parts are.
The buyer pays the premium and holds the right. The largest loss the arithmetic can produce on that side is the money paid, and it is a loss at every stock price on the wrong side of the strike. The gain grows with the share price, one multiplier × contracts for every 1.00 of share-price move past the breakeven.
The seller receives the premium instead of paying it. The largest gain the arithmetic can produce is the money received, at every stock price on the buyer's wrong side of the strike.
Past that line the two sides stop being symmetrical, and the page prints the arithmetic rather than a label:
Selling a call: profit or loss = money received − (stock at expiration − strike) × multiplier × contracts. There is no largest loss to write down. However high the share price finishes, the loss keeps growing with it — a stock at 200.0000 with a strike of 100.0000, one contract and a multiplier of 100.0000 is 300.00 − 10,000.00 = −9,700.00, and a stock at 300.0000 is 300.00 − 20,000.00 = −19,700.00. Nothing in the formula stops.
Selling a put: profit or loss = money received − (strike − stock at expiration) × multiplier × contracts, and the share price can only fall to zero. So the largest loss that can be worked out sits at 0.00: money received − strike × multiplier × contracts, which is the same figure as (strike − premium per share) × multiplier × contracts, written as a loss. The page prints both lines with your numbers when you are on that side.
No sentence here says which side is the better idea. The two paragraphs above are the same formula read with two different signs, and that is the whole difference between them.
The multiplier: 100 is a convention, not a law
Most US listed stock options cover 100 shares per contract, which is why this is the number in the box. It is a default, not a constant, and it is editable for a reason:
Adjusted contracts. When the underlying company splits its shares, pays a special dividend, spins something off or is taken over, the exchange can adjust the contract so it covers a different number of shares, or shares plus cash. The premium quote stays a per-share quote; the number of shares behind it changes.
Other markets and other products. Multipliers differ across exchanges and products, and index or non-US contracts can be written on something other than 100 units.
Your specification governs. The contract specification your broker publishes is the document that says what one contract covers. This page has no access to it, so it takes the number you type and multiplies by it.
The multiplier does not touch the breakeven price, because the breakeven is a per-share figure. It scales the money on both sides of the trade and nothing else. Type 10 instead of 100 on the example above and the money paid becomes 30.00 rather than 300.00, the position value becomes 100.00 rather than 1,000.00, and the breakeven stays at 103.0000.
At expiration, not before
This page values the contract at expiration, and it is deliberate about that. Before expiration an option usually trades for more or less than the gap between the share price and the strike, because it still carries time value and the possibility of a bigger move. Working that out takes an implied volatility, a number of days to expiration and an interest rate.
This page has none of them. It does not work out an implied volatility, it does not give the Greeks, and it puts no number on how likely anything is. What it does is take the stock price at expiration you type, work the contract out at that price with the max(0, …) line, and print the result. A figure for a contract before expiration would need a pricing model this page does not have, and a figure borrowed from one would not be arithmetic on the numbers you typed.
Time value cuts both ways, which is why the difference matters. An option that is out of the money at expiration is worth nothing, but the same contract with weeks left can still be sold for something. An option that is deeply in the money can trade below its intrinsic gap if it is hard to borrow or close to expiry. This page covers the expiration line only, and it says so rather than quietly mixing the two.
What is counted, and what is not
This page uses only the numbers you type. Nothing else goes into the arithmetic.
There is no option chain on this page. It does not know a strike, an expiry date, a bid, an ask or a last price for anything. Every box is yours to fill.
There is no live quote either. The premium and the stock price at expiration are both typed by you. This page never fetches a price and cannot show you one.
No implied volatility, no Greeks. There is no volatility input, no delta, no gamma, no theta, no vega and no rho on this page, and no time to expiration, so nothing here can be used as a price for an option today.
No chance of anything. The page prints the result at the price you type. It says nothing about whether that price will happen, and it has no field for a view on the direction of the share price.
Not counted: commissions, per-contract fees, exchange and regulatory fees, taxes, bid-ask spreads, slippage, dividends, early exercise, assignment, margin interest and the cost of the capital tied up. There is no field for any of them.
One contract, one side, one price at expiration. The page handles a single strike, bought or sold, valued at one stock price you choose. It cannot line up a spread, a straddle or any multi-leg position side by side, and it cannot import a list of trades.
One currency. The figures carry no currency. If a premium is quoted in one currency and a strike in another, the multiplication mixes them — convert first, because this page will not.
No advice. Nothing here says whether a strike is sensible, whether the premium is cheap or expensive, or whether to take either side of the contract. It is arithmetic on your own numbers.
Not built: saving your input, a history of previous runs, accounts or signing in. Nothing is stored and your numbers are not sent anywhere.
Frequently asked questions
What does an options profit calculator work out?
It takes a position in one option and works out what it is worth, and what it makes or loses, at a stock price you name. This page does that for a single contract at expiration: the money paid or received, the value of one share, the value of the position, the profit or loss, the return, the breakeven, and eleven stock prices at expiration with the result at each one.
Is an options profit and loss calculator the same tool?
Yes. "Options profit and loss calculator", "option payoff calculator", "call option profit calculator" and "stock option profit calculator" all describe the same piece of arithmetic, and this page is one: value the contract at a price, subtract the premium side, print the result. The name changes nothing about the formula.
How do I work out the profit on a call option?
Take the stock price at expiration, subtract the strike, and keep it at zero if that is negative — that is what one share is worth. Multiply by the contract multiplier and the number of contracts, and you have the value of the position. Subtract the money you paid for the whole position and you have the profit or loss. Add the premium per share to the strike and you have the breakeven. Every one of those lines is printed on the page with your own figures.
And the profit on a put option?
The same chain with the subtraction the other way round: one share is worth the strike minus the stock price at expiration, floored at zero. Everything after that — the multiplier, the contracts, the money paid, the breakeven — is the same arithmetic. Switch the first box to a put and the page reprints every line.
Can I use it for the sell side as well as the buy side?
Yes, that is the second box. The seller receives the premium and the result is the money received minus the value at expiration. The page also prints the two facts that differ between the sides: a seller's best result is the premium received, and on a short call there is no largest loss, because the loss keeps growing with the share price with nothing in the formula to stop it. On a short put the largest loss is (strike − premium per share) × multiplier × contracts, which the page prints with your numbers.
Where is the breakeven price?
In the result block, and it is one figure for both sides. For a call it is the strike plus the premium per share; for a put it is the strike minus the premium per share. Both the buyer and the seller of the same contract breakeven at that price, read from opposite sides: the buyer needs the share price to finish beyond it, and the seller is ahead while it finishes short of it.
Does it fetch the premium or the share price for me?
No, and it will not pretend to. There is no option chain and no quote feed behind this page, so both boxes are yours to fill. A page that fills them in is showing you its own data at its own moment in time, which is a different thing from arithmetic on numbers you chose.
Does it use implied volatility, or the Greeks?
No. There is no volatility box, no time-to-expiration box and no rate, so the page has nothing to price a contract before expiration with — and it does not try. It values the contract at the expiration you name, where the arithmetic is the max(0, …) gap between the share price and the strike. Delta, gamma, theta, vega and rho are not on this page at all.
Why can I change the contract multiplier?
Because 100 is the usual number, not the only number. Adjusted contracts after a split or a special dividend can cover a different number of shares, and multipliers differ across markets and products. The page starts the box at 100 because that is the common case, and it multiplies by whatever you type, because the contract specification you hold is the thing that governs.
Can I use this for employee stock options?
Only as a shape, not as a record. An employee grant has a grant price instead of a traded strike, no premium changing hands and no multiplier of 100 behind a listed contract, so what you would be typing is not the same object. The arithmetic here is about a traded contract with a premium, a strike and a specification. For a grant, use the numbers in your own plan documents.
Why is the profit or loss percentage shown against the premium?
Because that is the money the position itself moves: for a buyer it is the premium paid, for a seller the premium received. On the sell side that percentage is not a return on margin — the margin your broker requires is set by the broker and is not on this page, so a percentage of the premium is a share of the premium and nothing more. The page says so next to the line.
Does it work for a loss as well as a profit?
Yes. Type a price on the wrong side of the breakeven and the result comes back negative, and the table shows the loss at every price in the range. The optional target box takes a negative number too, so you can ask what stock price at expiration produces a loss of, say, −700.00, and the page works that price out.
Does it work on my phone, and do I need an account?
Yes to the first, and no to the second. The fields stack to one column on a narrow screen and the table scrolls inside the page rather than pushing it wide. There is no sign-up, no pop-up and nothing to install: the whole calculation runs in your browser.
Where to go next
The position size calculator works out how many shares fit inside a fixed risk per trade, from an account size, a risk percentage, an entry price and a stop. The stock profit calculator carries a share position through a sale and puts the fees on both sides, which is the same question this page answers for a contract rather than for shares.
This page is a calculator, not investment advice — it is arithmetic, not a recommendation to buy or to sell anything. Commissions, per-contract fees, taxes, spreads and slippage are not counted anywhere on this page. The premium and the stock price at expiration are both typed by you: there is no live quote here and no option chain. Contact: [email protected]