Options payoff calculator

How this is calculated

No hidden model and nothing fitted to data. Every figure on this page comes out of these lines, applied to the numbers you typed.

call at expiry   = max( 0, price - strike )
put at expiry    = max( 0, strike - price )
leg profit       = +/- ( intrinsic - premium ) x contracts x units
position profit  = sum of leg profits
break-even       = where position profit crosses 0
max loss         = unbounded when net short calls

The other three

Frequently asked questions

How do I read an options payoff diagram?

The horizontal axis is the price of the underlying at expiry; the vertical axis is your profit or loss at that price. Where the line crosses zero is a break-even. A flat section means the result stops changing beyond that price, which is what a bought or sold option at a further strike does, and a sloping section means profit is still moving one-for-one with the underlying.

Why does it only show the value at expiry?

Because valuing an option before expiry needs a pricing model and an implied volatility, and that is a different activity from arithmetic on the numbers you typed. A payoff at expiry is determined entirely by the strikes and premiums you entered; a mid-life value would be this tool's opinion about what an option is worth, which it deliberately does not have.

Why does max loss sometimes say Unlimited instead of a number?

Because it genuinely is. When a position is net short calls there is no ceiling on the underlying, so there is no floor on the loss. Printing whatever large number the plotted range happened to reach would understate the risk, so the tool refuses to put a figure there. The same is true of a short straddle or strangle on the upside.

Does this account for commissions, assignment or dividends?

No. Everything shown is at expiry and excludes commissions, exchange fees, early assignment on American-style options, dividends and any margin requirement your broker applies. An American option can be assigned before expiry, and a position can be far underwater long before the date the chart describes.

What is the contract multiplier?

How many units of the underlying one contract covers. A US equity option is usually 100 shares; an Indian index contract covers a fixed number of index units, and stock contracts differ per underlying. It multiplies both the premium you pay and the profit you make, which is why it is a field rather than an assumption.

Is my position data sent anywhere?

No. The whole calculation runs in your browser as JavaScript on this page. Your strikes, premiums and contract counts are never transmitted, never stored and never logged, and closing the tab discards them. A free account unlocks the calculator; it does not send anyone your numbers.