Free tools
Trading cost calculator
Commission, the bid–ask spread and slippage are paid on every trade, whether it gains or loses. Put in what you pay, how often you trade and an assumed average gross return per trade, and the calculator shows what the costs take over the years, set against the same trades at no cost. It is arithmetic on your own assumptions, not a forecast for any market or strategy.
What each trade costs
Your assumptions
In any currency; the fixed commission is in the same one.
Cost per round trip—of the position, at the starting balance
Gross return per trade to break even—
Yearly cost drag—
Gross balance—
Net balance—
Taken by costs—
Gross and net balance over the trades.
How it works
Every trade buys with the whole balance and later sells it: spot, long only, with no borrowing. Each trade earns the same gross return you entered. The gross line is that run with no costs; the net line is the same run with the costs taken off each trade.
One round trip pays the fixed commission twice (on the buy and on the sell), the percentage commission twice, the slippage twice and the spread once, because buying at the ask and selling at the bid crosses the full spread a single time. The percentage costs are taken as a share of the position at entry, so a round trip at balance E costs 2 × commission % + spread + 2 × slippage, plus 2 × fixed commission ÷ E.
The break-even gross return is that cost at the starting balance: a trade that earns exactly it ends where it began. The yearly cost drag is how far the net balance trails the gross one after the first year, as a share of the gross; the line beneath it adds up the year’s round trips without compounding. A fixed commission weighs less as the balance grows and more as it shrinks, so the cost per trade changes over the run.
What it leaves out
Real trades do not all earn the same return, and spreads and slippage widen and narrow with conditions. Taxes, account and data fees, currency conversion and minimum order charges are not included. Use it to see what a set of cost assumptions implies, not to judge whether those assumptions hold for any broker, market or strategy.