How Fees, Spread and Slippage Affect a Trade
Measure commission, bid-ask spread and slippage together to estimate all-in execution cost and breakeven movement.
The concept in plain English
An execution cost calculator combines commissions, bid-ask spread and expected slippage to estimate the all-in drag of opening and closing a trade. It also shows how far price must move before the trade breaks even.
Open Fee, Spread & Slippage CalculatorAvoid counting the same cost twice
A quoted bid-ask spread and measured execution slippage may overlap depending on the benchmark used. State whether slippage is measured against the midpoint, the quoted side or the decision price before adding the estimates. This tool assumes one full spread plus per-side commission and slippage on a constant trade value. It does not reconstruct individual fills. Compare its estimate with execution records to make future assumptions more realistic.
The price of a round trip
$10,000 trade value, 0.1% fee per side, 0.05% full spread and 0.02% slippage per side.
Fees = $20. Spread = $5. Slippage = $4. Total estimated cost = $29.
The modeled cost is $29, equivalent to a 0.29% move on the entry trade value.
The spread is counted once for the round trip. Entering a full round-trip slippage estimate as a per-side value would double it.
Calculation method
Round-trip cost adds entry and exit commission, spread paid across execution and slippage on both sides. Cost percentage divides total cost by position notional.
| Input | Purpose |
|---|---|
| Position value | Notional amount subject to costs. |
| Commission | Explicit venue or broker fee. |
| Spread | Difference between tradable bid and ask. |
| Slippage | Expected deviation from quoted execution price. |
Step-by-step workflow
- Enter the planned position notional.
- Add commission, typical spread and a realistic slippage assumption.
- Compare all-in cost and breakeven move across venues or order types.
Practical benefits
- Combines visible and hidden execution costs.
- Makes small-trade economics comparable.
- Supports broker and venue evaluation.
Questions about Fee, Spread & Slippage Calculator
What is the difference between spread and slippage?
Spread is the gap between quoted bid and ask. Slippage is the difference between the expected execution price and the actual fill.
Why calculate round-trip cost?
A completed trade usually pays costs both when opening and closing, so one-sided fees understate the price move needed to profit.
Can a zero-commission trade still be expensive?
Yes. Wide spreads, slippage, payment arrangements or poor fills can create significant cost even when explicit commission is zero.
Examples are hypothetical and exclude costs unless stated. This is educational material, not individualized investment or tax advice. Read our methodology and risk disclosure.