Position size calculator
Work out the largest position your own risk limit allows, from your account size, the percentage you are willing to lose, and where your stop sits.
Largest compliant size
0.41
Risk budget$250.00
Stop distance0.006000
Risk per unit$600.00
Truncated down, so the loss stays inside your budget. Before fees, spread, and slippage — each of those makes the real loss larger.
Run the full check →
Adds fees, slippage, your own rules, and what a gap through the stop would cost. Free, no account.
What this covers
Any instrument where loss scales linearly with distance and size — forex, futures, CFDs, spot crypto.
One position at a time. It does not know about anything else you have open.
Excludes fees, spread, and slippage — each of those makes the real loss larger than this figure.
Formula and assumptions
Risk budget = account equity × risk percentage.
Risk per unit = |entry − stop| × contract value.
Position size = risk budget ÷ risk per unit.
Assumes the stop fills at its price. It often does not; a gap fills worse.
Assumes the account value you entered is current and correct.
position_size.v1
Worked example
Example — not a recommendation.
Account$25,000
Risk per trade1% = $250
Entry → stop1.0840 → 1.0900 (60 pips)
Risk per standard lot$600
Largest compliant size0.41 lots
Common mistakes
Sizing from account balance rather than from the stop. The stop is what decides the loss.
Ignoring fees and spread, then wondering why the loss exceeded the budget.
Moving the stop closer to justify a bigger size — the same risk, worse odds of surviving noise.
Applying a percentage to a prop account as if the limit were yours rather than the firm's.
Limitations
This is arithmetic on numbers you supplied. It does not know your broker, your account, or the market. It does not predict price, does not say whether to take a trade, and is not advice. Maximelion is not affiliated with any broker or prop firm, and nothing here is endorsed by one.
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Last reviewed 25 July 2026