Position Size Calculator
Calculate the perfect lot size for your forex trades based on your account balance, risk percentage, and stop loss. Never risk more than you can afford on a single trade.
Need micro lot support? Not all brokers offer 0.01 lot trading. Compare brokers that support small positions.
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How to Use the Position Size Calculator
The position size calculator determines the optimal number of lots to trade so you never exceed your risk limit on any single trade. Enter four values: your account balance, the percentage you want to risk (we recommend 1–2%), your stop loss distance in pips, and the currency pair (which determines the pip value). The calculator does the rest.
The Position Sizing Formula
Where: Risk Amount = Account Balance × Risk Percentage
Example — $10,000 account, 2% risk, 50-pip stop loss on EUR/USD
Step 1: Risk amount = $10,000 × 2% = $200
Step 2: Pip value for EUR/USD standard lot = $10
Step 3: Position size = $200 ÷ (50 × $10) = $200 ÷ $500 = 0.40 lots
This means you should trade 0.40 standard lots (40,000 units). If your stop loss is hit, you lose exactly $200 — no more than 2% of your account.
Why Position Sizing is Critical
Position sizing is what separates professional traders from amateurs. Without it, you're essentially gambling.
Capital preservation: Even the best trading strategy will produce losing streaks. If you risk 10% per trade and lose 5 trades in a row, you've lost 50% of your account — and you need a 100% gain just to break even. With 2% risk per trade, the same 5-trade losing streak costs only 10%.
Consistency: By risking the same percentage on every trade, your position sizes automatically adjust as your account grows or shrinks.
Emotional control: When you know your exact maximum loss before entering a trade, you eliminate the anxiety of uncertainty.
The 1% and 2% Risk Rules
The 1% rule is considered conservative and is recommended for beginners. The 2% rule is the most common approach among experienced retail traders. Some aggressive traders risk up to 3–5%, but this significantly increases the risk of blowing the account.
Pro Tip
A trader risking 1% per trade can survive 100 consecutive losses before going bust. At 2%, they can survive about 50. At 5%, only 20. Choose your risk level based on your strategy's historical win rate and your emotional tolerance for drawdowns.
Position Sizing for Different Account Sizes
Position = $5 ÷ (30 × $10) = 0.017 lots → round to 0.02 lots
$5,000 account, 2% risk ($100), 40-pip SL, EUR/USD:
Position = $100 ÷ (40 × $10) = 0.25 lots
$50,000 account, 1% risk ($500), 25-pip SL, EUR/USD:
Position = $500 ÷ (25 × $10) = 2.00 lots
If you have a small account (under $1,000), look for brokers that support micro lots (0.01) or even nano lots (0.001).
How Stop Loss Distance Affects Position Size
There's an inverse relationship between your stop loss distance and your position size. A wider stop loss requires a smaller position to maintain the same risk amount. A tighter stop loss allows a larger position.
This is why scalpers (who use tight 5–15 pip stops) can trade larger lot sizes than swing traders (who might use 50–200 pip stops) while risking the same dollar amount.