Why position size matters
Two traders can take the same entry with the same stop and end the month very differently, because one risked 1% per trade and the other risked 10%. Position size decides how much a losing trade costs. This calculator turns the risk you choose into a lot size.
How to use the lot size calculator
- Enter your account balance and choose a risk per trade, as a percent or a fixed amount.
- Enter the distance to your stop loss in pips (or points for indices).
- Read the lot size. The calculator also shows the margin that size needs at your leverage and warns you if it is more than your balance.
Lot size = Money at risk ÷ (Stop loss in pips × Pip value per lot)
Lot size examples
| Account and risk | Trade | Lot size |
|---|---|---|
| $10,000, 1% ($100) | EURUSD, 25-pip stop ($10 per pip per lot) | 0.40 |
| $10,000, 1% ($100) | XAUUSD, $5 stop (50 pips) | 0.20 |
| $5,000, 0.5% ($25) | GBPJPY, 30-pip stop (about $6.35 per pip per lot) | 0.13 |
| $2,000, $20 fixed | NAS100, 40-point stop (contract size 1) | 0.50 |
Standard, mini and micro lots
| Lot | Size | Currency pairs | Gold (XAUUSD) |
|---|---|---|---|
| Standard | 1.00 | 100,000 units | 100 oz |
| Mini | 0.10 | 10,000 units | 10 oz |
| Micro | 0.01 | 1,000 units | 1 oz |
Why the result is rounded down
Most brokers accept lot sizes in steps of 0.01. The calculator rounds down to the nearest step, so the actual risk is never more than the amount you entered. It shows the actual risk at the rounded size too.