Trading Cost Calculator
Trading cost calculator
Cost per round trip
Total paid in costs
Capital left, break-even trades
Drag on capital
The scenario is deliberately neutral: every trade closes exactly where it opened, so the only thing changing your balance is cost. That isolates the drag. Costs compound — each round trip is charged on a slightly smaller balance — which is why the total is not simply the per-trade cost times the number of trades. On a "0.10% fee" venue a round trip actually costs about 0.24% once both sides and the spread are counted, and fifty of them remove roughly a ninth of the account without a single losing call. Funding on leveraged positions and tax are not modelled. Runs entirely in your browser. Not advice.
What this calculator does
It models a deliberately neutral trader. Every position closes at exactly the price it opened, so no trade wins and no trade loses. The only thing changing the balance is cost, which is what makes the drag visible.
The result
On a venue advertising “0.10% fees”, a round trip costs about 0.24% once you count the fee on the way in, the fee on the way out, and a modest spread on both sides. Fifty of those round trips remove roughly 11% of the account without a single incorrect call.
Note that it is not simply the per-trade cost multiplied by the number of trades. Costs compound: each round trip is charged on a slightly smaller balance than the last, which is why the honest total differs from the naive one — by about $68 on a $10,000 account over fifty trades in the default scenario. The difference grows with both the cost and the trade count.
Why the advertised fee is the smallest part
The headline fee is one of at least three costs, and usually the one you can most easily see. The spread you cross on entry and exit is a real cost even though no line item names it, and slippage on a thin book can dwarf both. Our article on the real cost of a trade works through this in more detail.
The practical implication is about frequency rather than skill. A strategy that needs many trades has to clear a cost hurdle that a patient one does not, and that hurdle is charged whether the strategy works or not.
What is not modelled
Funding payments on perpetual positions, borrowing costs, withdrawal fees, maker rebates and tax are all absent. Fee tiers that reduce your rate at higher volume are also absent — if you qualify for one, lower the fee input. Everything omitted here except the rebates and tiers pushes the real figure higher.
Frequently asked questions
What is a round trip? One entry and one exit. Two fees.
What should I put for spread and slippage? On a deep book for a major asset, a few hundredths of a percent per side is reasonable. On a thin pair it can be far more, and it is worst exactly when you most want to trade.
Does this mean trading less is better? It means trading more has a measurable cost that has to be earned back before anything else. Whether your edge exceeds it is not something this tool can know.
Is this advice? No. See our disclaimer.