Formula
The formula is displayed so the result can be checked independently. PreBreakout does not use a hidden scoring model on this page.
Worked hypothetical example
For a hypothetical long position entered at 100 with quantity 100, 0.10% entry fee, 0.10% exit fee, 2 of fixed round-trip costs, 0.05 spread cost per unit and 0.02 slippage allowance per unit, modeled break-even is about 100.2903, a favorable move of about 0.29%.
Important: the numbers are fictional and are not associated with a security, issuer or current market price.
What this calculator does not tell you
- Fee percentages are applied to the transaction notional on their respective side; fixed costs are allocated across the entered quantity.
- Spread and slippage inputs are round-trip per-unit allowances. If your entered execution values already include a cost, leave the matching field at zero to avoid double counting.
- The site does not estimate broker fees, spreads, slippage, swap, taxes, financing or contract multipliers. Enter only costs expressed in the units described on this page.
- The result is the arithmetic zero-net-P/L exit under the entered cost model. It is not a target, recommendation or forecast.
Break-even price is the inverse of a P/L calculation
A normal profit/loss calculator starts with an exit value and reports the result. This tool does the opposite: it solves for the exit value that makes modeled net P/L equal zero after the costs you entered. That distinction makes it useful when the question is “how far does price need to move just to cover my assumptions?” rather than “what happens at this exit?”
What the cost fields mean
Entry-side and exit-side fee rates are percentages of the respective transaction notional. Fixed costs are one round-trip cash amount for the whole entered quantity. Spread and slippage are entered as round-trip cost allowances per unit. The calculator does not infer any of them.
Avoid double-counting execution costs
If an entry or exit value already reflects bid/ask spread or a measured fill slippage, entering that same amount again as a separate spread/slippage allowance counts it twice. Keep the cost model consistent with how your input values were defined.
Why long and short formulas differ
For a long model, favorable movement means the exit must rise enough to cover costs. For a short model, favorable movement means the exit must fall enough. Percentage fees also depend on the exit notional, which is why the calculator solves the exit value algebraically rather than simply adding a flat number to entry.
How to use it for learning
Change one input or observation at a time and check how the output changes. The page reports only deterministic arithmetic from your inputs; it does not convert the result into a quality score, forecast or trading instruction.