Lot size calculator for gold & forex

The formulaLot size = amount at risk ÷ (stop-loss distance × value of that move for 1 lot). Enter your numbers below; the lot is rounded down to 0.01 so you never risk more than you chose.

—Lot size
—Amount at risk
—Loss per 1 lot at your stop
—Loss with 0.01 lot

Account currency: USD. Contract sizes differ between brokers — check Symbol Specification in MetaTrader and edit the field if yours is different.

Worked examples

Gold: $1000 account, 1% risk = $10. Stop $5 away × 100 oz = $500 per lot → 0.02 lot.

EURUSD: $1000 account, 1% risk = $10. Stop 20 pips × $10 per pip = $200 per lot → 0.05 lot.

Questions

How do I calculate lot size?
Lot size = the amount you risk ÷ (stop-loss distance × value of that move for 1 lot). Example: a $1000 account risking 1% risks $10. On gold with a $5 stop, one standard lot (100 oz) loses $500, so the lot is 0.02.
How much is a $1 move in gold per lot?
With the usual contract of 100 troy ounces, a $1 move in XAUUSD is $100 for 1 standard lot, $10 for 0.10 lot and $1 for 0.01 lot. Some brokers use a different contract size, so check Symbol Specification in MetaTrader.
What lot size for a $100 account on gold?
Risking 1% ($1) with a $3 stop needs about 0.0033 lot, which is below the smallest lot most brokers allow (0.01). At 0.01 lot that stop loses $3, which is 3% of the account — so either widen the account, tighten the stop, or accept the higher risk knowingly.
Why is the result rounded down?
Brokers accept lots in steps of 0.01. Rounding down keeps the real loss at or below the risk you chose; rounding up would quietly risk more.
Does the calculator send my numbers anywhere?
No. The calculation runs in your browser; nothing you type is sent to our server.

Educational tool, not investment advice. Leveraged trading carries a high risk of losing your capital.