Free trading tool
Forex Position Size Calculator
Calculate your position size based on your account balance, risk percentage, entry price and stop loss.
Position calculator
USD account · First-currency units
USD → AUD rate
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Results
Position size
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Units of AUD · First currency
- Risk amount
- $100.00
- SL distance
- —
- USD → first currency
- —
- Risk-to-Reward
- —
- Potential loss
- —
- Potential profit
- —
Waiting for a valid exchange rate.
Size = (Risk USD × USD/AUD × Entry) / SL distance
How the calculation works
Three inputs decide the size.
The position size is not a preference — it follows directly from how much you are willing to lose and how far your stop sits from your entry.
Set your risk
Choose the amount — or percentage — of your account balance you are willing to lose on the trade.
Measure the distance
The distance between your entry price and your stop loss defines how much room the trade has to move against you.
Get the size
Your risk amount and stop distance together determine the position size that keeps the loss within your plan.
Reading the result
Your size is counted in the first currency of the pair.
A currency pair always names two currencies. The first one — the base currency — is what your position is denominated in. A position on EUR/USD is measured in euros, a position on GBP/JPY in British pounds, and a position on USD/CHF in US dollars. One standard lot equals 100,000 units of that base currency, which is why the same lot count can represent a different monetary amount on different pairs.
Examples
Questions
Position sizing, answered.
Common questions about calculating position size in forex.
How do I calculate my forex position size?
Position size comes from the amount you are willing to risk divided by the distance to your stop loss, converted into the value of one unit of the base currency. You enter your account balance, risk percentage, entry price and stop loss, and the calculator converts that into a position size you can assess before entering the trade.
How much should I risk per trade?
Many traders risk between 0.5% and 2% of their account balance on a single trade. The exact number matters less than applying one consistent rule to every trade, so a single loss never damages the account beyond recovery.
What is a standard lot in forex?
A standard lot is 100,000 units of the base currency — the first currency in the pair. Smaller sizes also exist: a mini lot is 10,000 units and a micro lot is 1,000 units. The calculator shows its result in units of the base currency; divide by 100,000 to read it in standard lots.
Which currency is my position size expressed in?
The position size is expressed in units of the first currency of the pair — the base currency. A size on EUR/USD is counted in euros, a size on GBP/JPY in British pounds, and a size on USD/CHF in US dollars.
Does position sizing improve my win rate?
No. Position sizing does not change how often your trades win or lose — it controls how much each outcome costs or earns you. Its purpose is to keep any single trade from threatening the account, which makes results easier to evaluate over time.
Is the calculator free to use?
Yes. The forex position size calculator is free to use with no account or registration required.
From planning to review
Plan the trade. Then record it.
Pair the calculator with the Trading Journal to review every decision and keep your process deliberate.