“Quantity: 1” is incomplete information. It might mean one coin, one contract worth a fixed dollar amount, or one contract representing a fraction of a coin. Before checking a P&L result, identify the unit on the quantity field. Otherwise, even correct arithmetic can answer the wrong question.
Read four fields before choosing a formula
- Underlying asset: which market the contract follows.
- Price quotation: what one displayed price unit means.
- Contract size or multiplier: how contract count maps to exposure.
- Settlement asset: the currency in which gains and losses are credited.
Collateral is a separate field. A product may accept an asset as collateral without expressing its P&L in that asset. Kraken’s derivatives collateral documentation distinguishes its multi-collateral arrangements from coin-margined products. A wallet containing BTC is therefore not, by itself, enough information to select an inverse-contract formula.
Linear P&L follows the price difference
For the simple coin-quantity model used by our calculator, a long produces q × (exit − entry) quote units; a short reverses that price difference. Bybit’s USDT-contract calculation guide illustrates this linear relationship. Fees and funding are additional cash flows, not changes to the meaning of coin quantity.
Take an invented 0.05 BTC long with an entry of 20,000 and an exit of 25,000 quote units per BTC. Gross P&L is 0.05 × 5,000 = 250 quote units. A 0.10 BTC position at those same prices produces 500 units. Doubling quantity doubles this model’s price P&L; a leverage label does not need to be multiplied into it again.
Inverse P&L uses reciprocal prices
A common inverse structure has a fixed USD contract value but settles in the underlying coin. For that structure, a long’s gross coin P&L is USD contract value × (1 ÷ entry − 1 ÷ exit). A short reverses the reciprocal difference. The Bybit inverse-contract explanation documents this model. Always check the particular contract specification before applying it.
For an illustrative 1,000 USD contract value with entry 20,000 USD/BTC and exit 25,000 USD/BTC, the long’s gross result is 1,000 × (0.00005 − 0.00004) = 0.01 BTC. Valuing that result at the example exit price gives 250 USD. This is a conversion of the coin result at a specified price, not proof that coin collateral and stablecoin collateral have identical risk.
For a different exit at 16,000 USD/BTC, the inverse long’s result becomes 1,000 × (0.00005 − 0.0000625) = −0.0125 BTC, worth minus 200 USD at that exit price. Notice that the coin result is not simply a constant BTC quantity multiplied by the dollar price difference. Its settlement unit is doing important work.
Convert contract count only when the multiplier is known
Suppose a hypothetical linear specification defines one contract as 0.001 coin. Then 250 contracts represent 0.25 coin. Entering 250 in a calculator expecting coin quantity would overstate that exposure by a factor of 1,000. For a different product, a fixed dollar contract value would require a different conversion; do not assume the same multiplier from a familiar ticker.
A useful worksheet stores the raw contract count, the specification’s multiplier and the converted quantity in separate columns. Keep the specification URL beside them. If any one of these is missing, pause the calculation rather than replacing the missing unit with a guess.
Expiry and settlement are different classifications
“Perpetual” describes the absence of a fixed contract expiry; it does not mean “linear.” The Kraken derivatives overview covers different product structures. Read maturity, settlement and collateral as separate attributes instead of treating one name as a complete specification.
The CryptoToolDeck futures calculator accepts linear coin quantity or derives it from an explicitly simplified margin assumption. It does not accept inverse-contract count, quanto settlement or arbitrary multipliers. Its currency labels describe your inputs; typing a symbol does not verify that a real contract fits the model.
Educational information, not a wallet audit, transaction validation or personalised financial advice. Service support and interfaces can change. Report an error with the page URL; never send recovery phrases or private keys.