How to Calculate Lot Size for Gold (XAUUSD), With Calculator
The single most important number in a trade is not the entry or the target. It is the position size. Get it right and a losing trade is a small, planned cost. Get it wrong and one bad trade can undo a month of work. Here is how to size gold trades properly.
Step 1: decide how much you will risk
Most disciplined traders risk a fixed percentage of their account on each trade, usually between 0.5% and 2%. On a $5,000 account, 1% risk is $50. That is the most you are willing to lose if your stop loss is hit.
Using a percentage, not a fixed lot size, means your risk shrinks automatically during a losing streak and grows as the account grows.
Step 2: measure your stop loss distance
Your stop loss comes from the chart, not from your wallet. Place it where the trade idea is clearly wrong, for example below the last swing low on a buy. Then measure the distance in price. Entry 4,151.50 with a stop at 4,146.50 is a distance of 5.00.
Step 3: apply the formula
Because one lot of gold is usually 100 ounces, a $1.00 move is worth $100 per lot. The formula is:
Lot size = Risk in $ ÷ (Stop distance × 100)
Worked example: $5,000 account, 1% risk = $50, stop distance 5.00.
$50 ÷ (5.00 × 100) = 0.10 lots
If the stop is hit, you lose 5.00 × 100 × 0.10 = $50, exactly what you planned.
Calculator
Round down to your broker's lot step (usually 0.01). Check your symbol's contract size in MetaTrader under Symbol → Specification.
Quick reference table
Lot size for a $100 risk at different stop distances (100 oz contract):
| Stop distance | Lot size |
|---|---|
| 2.00 | 0.50 |
| 5.00 | 0.20 |
| 10.00 | 0.10 |
| 20.00 | 0.05 |
Notice the pattern: a wider stop means a smaller position. The dollar risk stays the same. That is the whole point.
Common mistakes
- Choosing the lot first. "I always trade 0.50" ignores the stop. A 20.00 stop at 0.50 lots is a $1,000 risk.
- Moving the stop to fit the lot. Tightening a stop just to trade bigger puts it where normal price noise will hit it.
- Forgetting the spread. Gold spreads can widen sharply around news. Leave a small buffer.
- Stacking trades. Two positions of 0.10 lots on the same idea is a 0.20 lot risk. Size the total, not each entry.
Next, learn where that stop loss should actually go in how to set stop loss and take profit.
This article is general education, not financial advice. Trading involves substantial risk, and you can lose more than you expect. Only trade with money you can afford to lose.