Options Profit Calculator

Break-even is the strike plus the premium, never the strike

The strike price is where the option starts having intrinsic value. It is not where you start making money. Between those two points sits the premium you paid, and that gap is the whole reason a position can be right about direction and still lose.

A long call breaks even at strike + premium. Buy the $100 call for $5.20 and the stock has to finish above $105.20 before you have made a cent. At exactly $100 — with the stock having gone precisely where you wanted it to sit — the option expires worthless and you are out $520 per contract. A long put is the mirror: strike − premium, so the same $5.20 premium on a $100 put needs the stock below $94.80.

That much is well known. Where it goes wrong is spreads. In a bull call spread you pay for one call and sell another, and the credit from the short leg reduces what the structure cost you. Buy the $100 call for $6, sell the $110 call for $2, and the break-even is $104 — the lower strike plus the net debit of $4. People routinely compute $106, using the premium of the long leg alone, and place their expectations two dollars too high.

This calculator does not carry a table of memorised formulas, one per structure. It finds the break-even by locating where the payoff function actually crosses zero, so a spread, a covered call and a naked put are all solved the same way and none of them can drift out of sync with the others. The verification suite checks that the price it reports produces a profit of exactly zero, to a tolerance of one part in a billion.

One contract is one hundred shares

Option premiums are quoted per share. Contracts are traded in lots of 100 shares. Almost every wrong options calculator on the internet fails at exactly this junction, and it fails by a factor of 100 — a mistake large enough to turn a $520 position into a $5.20 one, or a $960 profit into $9.60.

So a $5.20 premium is $520 of cash for one contract. Two contracts of that call is $1,040 out the door. If the stock finishes at $112, each contract is worth ($112 − $100) × 100 = $1,200, and the profit is $1,200 − $520 = $680 per contract. Break-even, by contrast, is a price per share and does not move with the number of contracts at all — a distinction worth holding on to, because size changes how much you win and lose, never where the line sits.

The multiplier is an editable field here rather than a constant buried in the code. Standard US equity options deliver 100 shares, but adjusted series produced by splits, mergers and special dividends can deliver something else entirely, and a tool that hard-codes 100 will calmly give you the wrong answer on those without saying so.

The maximum loss on a naked short call is unlimited

Sell a call without owning the shares, and without a long call above it to cap the damage, and your loss is whatever the stock finishes above the strike, minus the premium, times 100 per contract. Share prices have no ceiling. Neither does that loss.

This is the point where calculators lie most often, and they lie by accident. A tool that samples the payoff over some price range — say zero to twice the strike — and reports the worst value inside that window will print a large, specific, entirely plausible dollar figure. It looks like an answer. It is an artefact of the window. Widen the window and the number gets worse; there is no width at which it stops.

This page prints the word Unlimited, shows a red warning block, and reports no capital requirement, because the requirement on a naked short call is broker margin, recalculated daily, and it can grow along with the price. The maximum gain is the premium you collected and nothing more. That asymmetry — a capped gain against an uncapped loss — is the entire character of the position, and rounding it into a tidy number is the most expensive simplification in the subject.

A short put is different, and the difference is real. A stock cannot fall below zero, so the worst case is bounded: (strike − premium) × 100 per contract. Sell the $50 put for $2 and the floor is a $4,800 loss per contract, reached if the company goes to zero. Large, finite, and knowable in advance.

The five structures, side by side

A covered call is worth reading twice, because it is sold as a conservative position and its risk profile is not symmetric. Own stock at $98, sell the $105 call for $2.10: your upside is capped at $9.10 per share no matter how far the stock runs, and your downside is $95.90 per share, all the way to zero. The premium cushions the fall by exactly $2.10 and not a cent more. It is a trade of upside for income, not a hedge.

A cash-secured put has the payoff of a covered call, shifted. You set aside strike × 100 per contract, and if the stock falls below the strike you buy the shares at the strike using that cash. Your effective cost is the strike minus the premium, which is exactly the break-even the calculator reports.

This is the payoff at expiration, not the price today

Every number on this page describes expiration day, when time value has decayed to nothing and an option is worth precisely its intrinsic value. That makes the arithmetic exact and checkable, and it is why the payoff diagram is made of straight lines with a kink at each strike.

Before expiration, an option carries extrinsic value on top of that: time remaining and implied volatility, plus smaller effects from interest rates and dividends. A long call that this page shows as a $520 loss at $100 will usually still have real market value the day before expiry, and considerably more of it a month out. Pricing that requires a model — Black-Scholes or a binomial tree — fed with volatility and days remaining.

This calculator has no field for volatility, no field for days to expiry, and no field for interest rates. That absence is the design. A tool without those inputs cannot produce a mid-life valuation, and being unable to fake it is a better guarantee than a disclaimer.

Assignment, exercise and what actually happens at expiry

US listed equity options are American style: the holder can exercise on any business day up to expiration, so anyone short an option can be assigned at any time. Early assignment on calls clusters in the day before an ex-dividend date, when the dividend on offer exceeds the time value the holder would be throwing away. Puts get assigned early when they are deep in the money and there is little time value left to lose.

At expiration, the Options Clearing Corporation automatically exercises options that finish in the money by at least a cent, unless the holder instructs otherwise. That matters if you do not want the shares: an option that finishes one cent in the money still turns into a 100-share position per contract, with the cash requirement that comes with it.

Assignment converts an option into stock. A short call assigned means delivering 100 shares per contract at the strike; a short put assigned means buying them. This calculator models a position carried to expiration, so if a leg is assigned early the outcome will differ from what it shows here.

Tax treatment in the United States

Gains and losses on listed equity options are generally capital in nature, short-term if the holding period is a year or less. Given typical option lifetimes, most outcomes land in the short-term bucket and are taxed at ordinary income rates rather than the preferential long-term rates.

Premium received for writing an option is not taxed when it is received. The result is determined when the position closes, expires or is assigned. If a short put is assigned, the premium generally reduces the cost basis of the shares acquired; if a short call is assigned, it generally increases the proceeds of the shares sold. Index options that qualify under Section 1256 follow a different regime altogether, with mark-to-market at year end and a fixed 60% long-term, 40% short-term split regardless of holding period.

None of that is computed here, and none of it is advice. This page calculates the payoff of a structure you described; the tax consequences depend on your own circumstances and on rules that change.

What this tool does not do

• It gives no investment advice. It does not suggest a strike, a structure, an expiry or a direction. It does not tell you whether a position is a good idea, and it makes no forecast of any price. It computes a structure you described, and nothing else.
• It does not price options before expiry. No Black-Scholes, no greeks, no implied volatility, no probability of profit. Those all require inputs this tool deliberately does not collect.
• It ignores commissions, exchange and regulatory fees. Per-contract costs are real and they matter most on small positions; fold them in yourself.
• It does not calculate your tax in any jurisdiction. The tax section above is background reading, not a computation.
• It models expiration only. Early assignment, rolling, closing a leg before expiry, dividends and adjusted contract terms are all outside its scope.

Privacy

Strikes, premiums and position sizes never leave your browser. There is no account, no logging, no upload and no server-side calculation. That matters more here than on most tools, because what you would be typing is the size and cost of a position you actually hold.