Trading fees and funding are usually calculated from exposure under the contract's rules, not simply from the margin you deposit.
Start with the contract
Perpetual products do not all use identical settlement, collateral, contract sizes, or funding mechanics. Read the specification for the exact instrument and venue. A familiar BTC symbol can hide different multipliers or payout formulas, and a calculator designed for a simple linear position may not apply to an inverse or quanto contract.
This guide and calculator use a simplified linear USD notional model. They estimate selected costs and exclude price profit or loss. They do not calculate liquidation levels, collateral haircuts, portfolio offsets, or the cash needed to survive a particular price path. Treat the output as an itemized arithmetic example, then verify the actual contract rules.
Notional versus margin
Notional describes exposure; margin describes collateral supporting it. A hypothetical $10,000 position backed by $1,000 of initial collateral has ten times as much notional as that collateral amount. That relationship does not make the position's trading fees equivalent to the fees on a $1,000 trade.
Changing leverage while holding notional constant does not, by itself, reduce a notional-based fee. It changes the collateral relationship and can affect how close the position is to a margin boundary. Conversely, holding collateral constant and increasing notional increases both exposure and any costs calculated from that notional. Keep these two experiments distinct when comparing scenarios.
Entry and exit fees
Calculate an entry fee from the entry notional and applicable fee rate. Calculate an exit fee separately from the exit notional and its rate. A marketable order may incur taker fees; whether an order qualifies as maker liquidity depends on how it interacts with the book and on the venue's rules.
At an illustrative $10,000 notional and five basis points on each side, entry costs $5 and exit costs another $5 if the notional stays unchanged. The total is $10 before funding, spread, and slippage. If the market price or position size changes, exit notional can change too. The calculator's constant-notional assumption deliberately leaves that variation out.
Funding direction
Funding is a periodic transfer or adjustment defined by the product's rules. Under a common convention, a positive funding rate means longs pay and shorts receive; a negative rate reverses that direction. Verify the venue's sign convention and whether the quoted figure is a per-interval rate, an annualized display, or something else.
The calculator follows the positive-rate-longs-pay convention. It treats a positive result as a cost and a negative result as a funding credit. This sign choice appears beside the inputs and in the result so a short position does not silently become a long in the arithmetic. A funding credit is not the same as total trading profit.
Intervals matter
A funding rate cannot be interpreted without its interval. A displayed 0.01% per payment is different from 0.01% per day or per year. The number of payment events during a holding period depends on the product's schedule and eligibility rules, not just on how many hours the trade remains open.
In a simplified example, $10,000 multiplied by 0.01% produces $1 per funding event. Three events at an unchanged rate and notional produce a $3 long-side cost or a $3 short-side credit. Real rates and exposure can change between events. The model uses the number of events you enter rather than guessing an exchange schedule from a duration.
Add execution costs
A published trading fee is only one part of execution. The bid-ask spread and the difference between an observed quote and the eventual fill can change the entry and exit outcome. Larger orders may interact with several book levels. A low fee tier can therefore coexist with a worse overall execution result.
The calculator does not add a spread or slippage estimate because the relevant assumptions depend on order size, liquidity, market conditions, and execution method. Add these separately when comparing a full trade scenario. Do not subtract the same effect twice if your simulated entry and exit prices already include it.
Work the example
Take a constant $10,000 position, five basis points on entry, five on exit, and three funding events at positive 0.01%. The selected costs for a long are $5 plus $5 plus $3, totaling $13. The same assumptions for a short give $5 plus $5 minus $3, totaling $7. This is a cost difference, not a forecast of which direction will be profitable.
If funding becomes negative, the calculator reverses which side pays. If there are no funding events, it reports zero funding. With a sufficiently large funding credit, the selected-cost total can be negative; that means the modeled credit exceeds the modeled trading fees. It still says nothing about price losses, collateral risk, or other excluded costs.
Compare consistently
Use the same notional, entry method, exit method, holding assumptions, and settlement units across alternatives. Record the rate source and the time it was observed. A comparison mixing one venue's current funding with another's historical average has changed the experiment and should explain why.
Before relying on a result, reconcile the model with a venue statement containing actual fills, fees, and funding adjustments. Differences identify missing assumptions, rounding conventions, or product rules. This site supplies a transparent starting model and terminology; it does not supply live exchange rates, trade recommendations, or a promise that funding income will offset market risk.
Primary sources
Read the original documentation for product-specific details. Our examples simplify the arithmetic and do not reproduce all contract or service rules.
Work your own example
Estimate entry fees, exit fees, and constant-rate funding. All rates are your assumptions, not current exchange quotes.
Open calculatorPrepared using AI-assisted drafting. No independent professional review or hands-on product test is claimed. Editorial policy · Affiliate disclosure