Gold XAUUSD lot size calculator
Before entering a trade, know how much you lose if price reaches your stop loss. This tool works backwards from the amount you accept to lose to the lot size that fits your stop distance.
Formula checked against worked examples · Last reviewed 2026-10-05
Formula: amount at risk ÷ (stop distance × contract size), rounded down to 2 decimals. Check the minimum lot and contract size of your account. Price can gap past your stop loss (slippage), so the real loss can be larger than calculated.
How to use
- Enter your account balance in US dollars.
- Enter the percentage you accept to lose per trade (many traders use 1–2%, but the number is your own decision).
- Enter the stop loss distance in dollars per ounce and check the contract size of your account.
Formula
Lot size = (balance × risk %) ÷ (stop distance × contract size), rounded down to two decimals
Example
Balance 1,000 USD, risk 1% = 10 USD, stop distance 5 USD per ounce, contract size 100 oz: 10 ÷ (5 × 100) = 0.02 lot.
Hypothetical example to explain the formula. It is not real market data and not a trading recommendation.
Frequently asked questions
- What is the contract size for gold?
- It differs by broker and account type. Many accounts use 100 ounces per 1 lot, but check the specification of the account you actually use.
- Why can my real loss exceed the calculated one?
- Price can gap past your stop during news or market opens (slippage), and spread adds cost. The result is an estimate.
Limits and risk
This tool is educational. Results are estimates from the numbers you enter and are not investment advice. Trading CFDs is high risk and you can lose everything. Read the full risk warning
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