Forex Lot Size Calculator (Position Size Calculator)
Enter your account balance, how much you're willing to risk, and your stop loss. The calculator gives you the exact position size, so every trade risks the same amount no matter how wide the stop is.
Position size = (account balance x risk %) divided by (stop distance in pips x pip value per lot). Risking 1% of a $10,000 account with a 20-pip stop on EUR/USD, where one standard lot is about $10 per pip, gives 0.50 lots. Size from the stop distance, never a fixed lot.
Lot size calculator
Maths: lots = (balance × risk%) ÷ (stop in pips × pip value per lot). Standard lot = 100,000 units (gold: 100 oz). Check your broker's contract size before trading.
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See what the desk does →How the lot size formula works
Position size comes from three numbers: how much money you are prepared to lose, how far away your stop loss is, and how much one pip is worth for the pair you trade.
Example: a $10,000 account risking 1% is willing to lose $100. On EUR/USD one standard lot is worth about $10 per pip, so a 20-pip stop costs $200 per lot. $100 ÷ $200 = 0.50 lots. Widen the stop to 40 pips and the size halves to 0.25 lots, while the dollar risk stays at $100.
Standard, mini and micro lots
| Lot | Units of base currency | Approx. pip value on EUR/USD |
|---|---|---|
| Standard (1.00) | 100,000 | $10 |
| Mini (0.10) | 10,000 | $1 |
| Micro (0.01) | 1,000 | $0.10 |
Gold (XAU/USD) is usually quoted with a 100-ounce standard lot, where a $0.10 move is treated as one pip on most platforms. Contract sizes differ between brokers, so always check the symbol's contract specification.
Sizing is maths; spotting a clean setup is a skill. Chart Bound drills setup-reading on real historical charts, free.
Play free, no signup →Why size from the stop, not a fixed lot
Many beginners trade the same lot size every time. That means a trade with a wide stop quietly risks two or three times more than one with a tight stop. Sizing from the stop keeps every loss the same size, which is what makes a trading record readable: you can compare trades, measure your average win in "R" (multiples of what you risked) and see whether your process actually works.
How much should you risk per trade?
There is no universal number, but many professional and prop-firm traders keep risk per trade small, commonly in the 0.25% to 1% range, because a losing streak is normal in any method. At 1% risk, ten losses in a row costs roughly 10% of the account. At 5% risk the same streak costs about 40%, and recovering from a 40% drawdown needs a 67% gain.
Crosses and non-USD accounts
If neither currency in the pair is your account currency (for example EUR/GBP on a USD account), the pip value has to be converted. The calculator asks for the USD value of one unit of the quote currency (for EUR/GBP that's the GBP/USD rate) and does the conversion for you.
Frequently asked questions
How do I calculate lot size in forex?
Divide the amount you are willing to risk (balance times risk percentage) by the cost of your stop loss per lot (stop distance in pips times the pip value of one lot). The result is your position size in lots.
What lot size should I use for a $1,000 account?
It depends on your stop, not the account alone. Risking 1% ($10) with a 20-pip stop on EUR/USD, where a micro lot is about $0.10 per pip, gives 0.05 lots (five micro lots).
Is 0.01 lot a micro lot?
Yes. 0.01 lots is one micro lot, which is 1,000 units of the base currency, roughly $0.10 per pip on EUR/USD.
Does the calculator work for gold?
Yes. Choose XAU/USD. It assumes the common 100-ounce contract and a 0.10 pip size; check your broker's specification, because some use different gold contract sizes.
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Sizing is maths; spotting a clean setup is a skill. Chart Bound drills setup-reading on real historical charts, free.
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