Position Size Calculator.
The single most important calculation in trading. Tell it what you're willing to lose on the trade and where your stop sits, and it returns the exact lot size that keeps risk at that fraction of your account — across EUR/USD, GBP/USD, USD/JPY, gold and Bitcoin. Used by professionals on every entry, ignored by most retail traders who instead size by feel. Size first, click second. The maths takes ten seconds and is the difference between a controlled drawdown and a blown account.
Inputs
Your trade
Most pros stay between 0.5% and 1% per trade.
Pip value used: $10.00 per pip per 1.00 lot.
Result
Suggested position
Pip values are approximations for USD-denominated accounts at indicative spot. Confirm against your broker before sending the order.
The formula
Position sizing is fixed fractional risk. Pick a percentage of your account you can comfortably lose on any single trade — typically 0.5% to 1% — and translate that into lots through the pip value of the instrument.
Formula
Lots = (Balance × Risk%) ÷ (StopPips × PipValuePerLot)
- Dollar risk — what you stand to lose if the stop is hit. Treat this as the price of the trade.
- Pip value — roughly $10 per pip on a 1.00 lot of EUR/USD, GBP/USD and gold; about $6.70 on USD/JPY near current spot.
- Notional — lots × contract size × price. Confirm your broker has enough free margin to hold the position.
- Worked example — $10,000 account, 1% risk = $100. EUR/USD 25-pip stop. Lot size = 100 ÷ (25 × 10) = 0.40 standard lots.