Gold (XAUUSD) Lot Size: The Calculation, Worked Through

Quick answer

Gold lot sizing has one formula and one trap. The formula:

Lot size = (Account balance × risk %) ÷ (Stop distance in points × dollar value per point for 1 lot)

The trap: traders who are used to forex majors apply forex-sized lots to gold and end up risking three to five times what they intended, because gold's dollar-per-point value and typical stop distance are both larger.

The number to learn once

At most brokers, one standard lot (100 oz) of XAUUSD moves roughly $1 per $0.01 (one point) of price movement. Confirm this against your specific broker — gold contract specifications are not standardised the way forex pairs are, and it is the single most important number in this calculation.

Once you have it, the formula is mechanical.

Worked example

$100,000 account, 0.5% risk per trade = $500. Gold stop at $6 (600 points at $0.01 increments).

Step 1: Dollar risk ÷ stop distance in dollars = $500 ÷ $6 = $83.33 tolerable loss per $1 of adverse movement

Step 2: Convert to lots. If 1.0 lot loses $100 per $1 move (standard contract, confirm with your broker), then:

$83.33 ÷ $100 = 0.83 lots

Round down to 0.8 lots for a clean number and a small margin of safety.

Across account sizes

All at 0.5% risk, $6 stop, using $100 per $1 move for 1.0 lot — confirm your broker's actual contract specification before trading:

Notice these are small numbers relative to what many traders instinctively use on gold. That gap is the entire problem this article addresses.

Why gold catches traders who size like forex

A EURUSD trader risking 0.5% on a $100,000 account with a 20-pip stop might trade 2.5 lots comfortably. Move to gold with the same instinct — "2.5 lots feels normal" — and a $6 stop now risks $1,500, three times the intended amount.

The reason: gold's dollar-per-point value per lot is roughly 10 times larger than a typical forex pair's, and its normal stop distance in price terms is also wider. Both factors compound in the same direction. Traders who do not recalculate specifically for gold are almost always oversized on it, often without realising by how much.

Stop distance comes first, not lot size

The order of operations matters. Decide your stop from market structure — a swing high or low, or a multiple of current ATR — then calculate the lot size that keeps that distance within your dollar risk.

Doing it backwards — picking a lot size you're comfortable with and setting a stop to match — produces stops with no relationship to where gold actually invalidates your setup. You end up stopped out by noise, or exposed well past the level that should have ended the trade.

Reasonable stop ranges, though these shift with volatility regime and should be checked against current ATR rather than memorised:

Gold's ATR moves meaningfully between quiet and volatile weeks. A $5 stop that was reasonable in a calm period can be tight enough to get clipped by normal noise once volatility expands — recalculate rather than reuse a fixed number.

Sizing for the drawdown, not just the trade

Position sizing decides two things at once: the risk on this trade, and how many losing trades your account can absorb.

On a Pay After Pass evaluation — 15% static drawdown, 8% daily limit — 0.5% risk per trade gives you 30 consecutive losers of room before the maximum drawdown, and 16 before the daily limit. That headroom matters specifically for gold, because its wider excursions mean a "normal" losing trade can occasionally travel further against you than a forex loss would.

On the funded stage, the daily limit tightens to 3%. The same 0.5% risk gives you 6 losses of daily room — still workable, but with much less margin than the evaluation had. This is the reason to size from the funded rules from day one rather than adjusting after you pass. How to trade gold on a prop firm.

A five-step process

1. 1Identify your stop from structure or ATR, in dollars
2. 2Confirm your broker's contract value — dollars per point for 1.0 lot
3. 3Calculate: (Account × risk%) ÷ (stop × dollar value per point)
4. 4Round down, never up, for a margin of safety
5. 5Re-run the calculation whenever your stop distance or account balance changes materially

Use the position size calculator to automate this for your exact account size and current stop, and the drawdown calculator to see how many losing trades your program's limits actually allow.

Common mistakes

• Applying forex-sized lots to gold without recalculating — the single biggest cause of oversized gold positions
• Using a fixed stop in dollars regardless of current volatility, rather than checking ATR
• Increasing lot size after a losing gold trade to make it back — the position sizing equivalent of revenge trading
• Ignoring spread widening around news, which effectively moves your stop further without changing your intended lot size
• Not confirming contract specifications with your specific broker before assuming $1 per point

Bottom line

Gold's dollar-per-point value is roughly ten times a typical forex pair's, and its normal stop distance is wider too — both push in the same direction, toward traders being unintentionally oversized. Fix your stop from structure first, calculate the lot size that fits your dollar risk, and round down.

At 0.5% risk with a properly sized stop, gold is entirely tradeable inside a Pay After Pass evaluation's 15% of static room. Start from $9.99, or size your first trade with the position size calculator.

Related: How to trade gold on a prop firm · Gold trading mistakes that fail challenges · Best time to trade gold

Educational guide. Confirm exact contract specifications and pip values with your broker — these vary by platform. Not financial advice.