Trading Fees and Slippage Calculator

Estimate how entered commissions and execution slippage change the result of repeated trades. Enter gross profit or loss per round trip, entry and exit trade values, cost assumptions, and the number of similar round trips. The calculator uses your inputs and does not retrieve brokerage or market data.

Calculator

Enter trade and cost assumptions to estimate a net result.

Slippage is modeled as a percentage of each side's entered trade value. Actual execution costs can differ. Not financial advice.

Formula, inputs, and source

Formula: Across repeated round trips: gross total = gross P&L per trip × count; commission = (entry value + exit value) × commission rate per side × count; slippage uses the same base × basis points ÷ 10,000 × count; net = gross − both costs.
Inputs and units: Gross P&L, entry and exit trade values in currency; commission percent and slippage basis points per side; whole round-trip count.
Output and limits: Estimated aggregate commissions, slippage, and net result. Assumes identical trades and symmetric per-side cost rates; does not model variable fills, spread, market impact, exchange charges, financing, or taxes.
Source and version: Source: FINRA Fees and Costs investor guidance, accessed 2026-11-03, for trading-cost context. Cost arithmetic uses entered assumptions; reviewed 2026-11-03.

What does a trading fees and slippage calculator estimate?

This calculator estimates total modeled commissions, slippage, and profit or loss after those costs for a set of identical round trips. A round trip here means one entry and one exit. You provide the gross result and trade values for one round trip, the commission rate charged on each side, the slippage assumption for each side, and the number of round trips.

FINRA explains that transaction-based fees may be charged when buying or selling, and other costs can apply depending on the account and investment. Its investor guidance encourages investors to understand the costs of buying and selling. See FINRA, Financial Tips for New Investors and FINRA, The Basics of Selecting Investments (accessed 2026-11-03). Review your broker's fee schedule, confirmations, and applicable product documents for actual charges.

For each round trip, modeled commission is (entry value + exit value) × commission rate. Modeled slippage is (entry value + exit value) × slippage basis points ÷ 10,000. Total costs multiply the per-round-trip amount by the count. Net result is gross profit or loss multiplied by the count, less total modeled costs. A basis point is one hundredth of one percent, so 100 basis points equal 1%.

For example, with an entry value of 1,000, exit value of 1,025, a 0.10% commission rate per side, and 5 basis points of slippage per side, costs are estimated across both sides. The default number of round trips is only an editable illustration. It is not a claim about typical fees or execution.

The estimate treats the entered values as the amounts on which commissions and slippage apply. It assumes the same amounts and cost rates for each round trip, and treats slippage as an additional execution cost beyond the entered gross profit or loss. It excludes taxes, exchange or regulatory charges, spread estimates not represented by slippage, financing or borrow charges, market impact, rebates, tiered pricing, minimum commissions, and currency conversion. Actual costs depend on the broker, instrument, venue, order, and execution. Compare the estimate with actual trade confirmations.

Frequently asked questions

What is slippage in this estimate?

It is an entered assumed execution cost, expressed in basis points of each side's trade value. It is not measured from live quotes or fills.

Does the commission rate apply once or twice?

It applies to both entry and exit values for each round trip. Enter the per-side rate shown by your fee schedule.

Does it include spread, taxes, or exchange fees?

No. Only the entered commission rate and slippage assumption are modeled. Other costs may apply and should be checked separately.

Why can actual net results differ?

Actual charges, fills, trade values, and execution conditions can differ from the repeated assumptions. Use confirmations and your broker's current schedule to review actual costs.

Formula and attribution

Last updated: 2026-11-03

Per round trip, modeled commission = (entry trade value + exit trade value) × commission rate per side. Modeled slippage = (entry trade value + exit trade value) × slippage basis points ÷ 10,000. Total modeled costs multiply each per-round-trip cost by the number of identical round trips. Estimated net result = gross profit or loss per round trip × count − total modeled costs.

gross_profit_or_loss_per_round_trip (user-selected currency): Gross result before modeled commission and slippage for one assumed entry and exit.
entry_trade_value (user-selected currency): Nonnegative entry amount used as the fee and slippage base for each round trip.
exit_trade_value (user-selected currency): Nonnegative exit amount used as the fee and slippage base for each round trip.
commission_rate_per_side (percent): User-entered commission percentage applied to both entry and exit values.
slippage_per_side (basis points): User-entered execution-cost assumption applied to both trade values; 100 basis points equals 1%.
round_trip_count (whole round trips): Number of identical round trips from 1 to 1,000,000.

Output (user-selected currency): Gross result, modeled commissions, modeled slippage, combined costs, and estimated net result; excludes taxes, exchange/regulatory charges, financing, and other unentered costs.