Calculators / Position size
Forex Position Size Calculator
Enter your account balance, how much you're willing to risk, and your stop-loss in pips. You'll get the exact position size — in lots and units — that keeps your loss at exactly that amount if the stop is hit.
Position size
How many lots for a given account risk and stop distance. Pip value is derived from the instrument and your account currency.
How position size is calculated
- Risk amount = account balance × risk % — e.g. $10,000 at 1% risk = $100 you’re willing to lose on this trade.
- Pip value per lot = pip size × contract size, converted to your account currency if the pair’s quote currency differs from it.
- Position size (lots) = risk amount ÷ (stop-loss in pips × pip value per lot).
Worked example: a $10,000 account risking 1% ($100) with a 20-pip stop on EUR/USD, where a standard lot’s pip value is $10: position size = $100 ÷ (20 × $10) = 0.5 lots. If the stop is hit, the loss is 20 pips × $10 × 0.5 lots = $100 — exactly the 1% that was budgeted.
Position sizing is the only risk control you fully choose
You can’t control whether a trade wins. You can control exactly how much you lose if it doesn’t — and that’s entirely a function of position size. Two traders can take the identical setup, on the same pair, at the same stop-loss distance, and still have wildly different outcomes over 100 trades purely because one sized every position to a fixed % of account and the other guessed lot sizes by feel.
Sizing correctly before the trade is half the discipline. The other half is checking, afterwards, that you actually did it — across your last 20 trades, not just the one you remember. PipFlo’s trading journal logs your risk amount on every trade and flags the ones where you drifted from plan.
Position sizing questions
What is position size in forex?
Position size is how many units — or lots — of a currency pair you trade. A standard lot is 100,000 units of the base currency, a mini lot is 10,000, and a micro lot is 1,000. The right position size is the one where hitting your stop-loss costs you the exact dollar amount you decided to risk, not more.
How do I calculate forex position size?
Divide the amount you're willing to risk (account balance x risk %) by the value of your stop-loss in the account currency. Stop-loss value is your stop distance in pips multiplied by the pip value per lot. This calculator does that division for you, including the currency conversion when the pair's quote currency isn't your account currency.
How much should I risk per trade?
Most risk frameworks suggest 0.5–2% of account balance per trade. At 1% risk, a losing streak of 10 trades in a row costs roughly 10% of the account (slightly less, since each risk is a % of a shrinking balance) — survivable. At 5% per trade, the same streak wipes out over 40%. Lower risk per trade means you can be wrong many times in a row and still be trading.
Why does the pair matter for position size, not just the stop-loss?
Pip value differs by pair. On EUR/USD a pip is worth about $10 per standard lot; on USD/JPY it's calculated differently because JPY pairs quote to 2 decimal places instead of 4. If the quote currency isn't your account currency (e.g. you trade EUR/USD with a GBP account), the pip value also needs converting at the current exchange rate — which is what the conversion-rate field does.
Does this calculator account for leverage or margin?
No — position size and margin are two different limits. This calculator tells you the lot size that matches your intended risk. Your broker's margin requirement tells you whether your account has enough free margin to open that size at all. Check both before placing the trade.