XAUUSD Lot Size Calculator
By Aiobot · Oct 16, 2026
XAUUSD lot size = risk amount ÷ (0.01 price steps × value of one step per 1.00 lot), then rounded down to the lot step. On a $10,000 balance at 1% ($100), 50 steps, and a step value of 1, that is 2.00 lots. The step value of 1 is a teaching contract (100 troy ounces, USD account), not your broker’s tick. Promax percent mode uses the MT5 Balance line and the symbol’s tick value.
Lot size calculator
Risk amount ÷ (stop distance × value of 1.00 lot), then rounded down to the lot step you set. Forex defaults match the EUR/USD example: 0.20 lots.
Lot size = risk amount ÷ (stop loss × pip value of 1.00 lot), then rounded down to the lot step.
Risk amount = balance × risk % ÷ 100. If you type a maximum risk or a remaining daily loss room, the smaller of those figures is used.
Promax percent mode uses the MT5 Balance line, not equity. Floating loss is not inside this percent. Guard watches equity only while Active on a licensed real or prop account.
Assumptions
Forex assumption: a USD account and a pair quoted in USD, such as EURUSD. 1.00 lot = 100,000 units. One pip = 0.0001, so the pip value of 1.00 lot = 10. USDJPY and crosses are not this figure. Replace the pip value with the MT5 Specification.
Gold / XAUUSD assumption, not a live quote: 1.00 lot = 100 troy ounces, account in USD, one step = a 0.01 price move. That step is worth 1 per 1.00 lot. If your contract is different, or you count 0.10 as a pip, type the Specification value.
Index assumption: there is no shared point value for NAS100, US30, or GER40. This tool does not guess one. Type the point value of 1.00 lot from the symbol Specification.
Calculated lot size
Rounded down to your lot step, not to the nearest step.
The raw size is below one lot step, so the result is 0.
Risk amount used:
Educational estimate only. It does not send orders, does not know your broker contract, and does not guarantee a fill or a profit.
Inside MT5, Aiobot can size from a percent, a money amount, or a fixed lot. With a license on a real or prop account, Guard can enforce loss limits you define. A demo account does not need a license; Guard stays locked there. This tool does not price a plan.
What does an XAUUSD lot size calculator do?
It turns a risk amount and a stop distance into a lot size for gold. It does not choose the trade, send an order, or promise a result.
How do you calculate XAUUSD lot size?
- Take the risk amount as balance × risk percent ÷ 100. On a $10,000 balance at 1%, that is $100. Promax percent mode uses the MT5 Balance line, not equity. Floating loss is outside this percent.
- Measure the stop in 0.01 price steps. A 0.50 move on the gold price is 50 steps.
- Use the value of one 0.01 step per 1.00 lot. The teaching contract is 100 troy ounces in a USD account, so one step is 1. If Specification shows another tick value, type that instead. Promax reads the symbol tick value from the broker.
- Lot size = risk amount ÷ (steps × step value), then round down to the lot step. $100 ÷ (50 × 1) = 2.00, and a 0.01 step keeps 2.00 lots.
The calculator on this page opens on gold with those defaults. Rounding down can show 0 when the raw size is below one step. Promax rounds to the broker lot step and will not go below the symbol minimum, so the ticket on the chart can differ by one step.
Why is XAUUSD lot size different from EURUSD?
EURUSD often uses about $10 per pip per 1.00 lot. Gold does not. Reusing 10 on XAUUSD sizes the trade as if it were a currency pair. The same formula for forex and indices is on how to calculate lot size.
Does this replace the lot inside MetaTrader 5?
No. On the chart, Promax sizes from a percent of balance, a money amount, or a fixed lot, using the Entry and SL lines you place. You still choose the entry. Guard watches equity limits you type, and only while Active. A demo account runs Promax without a license; Guard stays locked there. A real or prop account needs the offline key: demo versus live.
Busier gold hours are a liquidity note, not an entry: best time to trade gold. Money left under a loss limit: daily and maximum drawdown.
Aiobot is not a signal service and does not guarantee a profit.