Position Size Calculator for Prop Firm Traders

Lot size = (account size × risk %) ÷ (stop loss in pips × pip value per lot). Example: $100,000 account, 1% risk ($1,000), 25-pip stop on EURUSD ($10/pip per standard lot) → $1,000 ÷ (25 × $10) = 4.0 lots. Most prop traders should risk 0.5–1% per trade.

Risk 0.5–1% per trade. At 1% you need 5 same-day losers to breach a 5% daily limit and 10 consecutive losers to breach a 10% max drawdown — comfortable survival margins. Note that FTMO now enforces a 0.5–1% per-trade cap on funded accounts, so practicing at that level also future-proofs your habits.

At most prop firm brokers, 1 standard lot of XAUUSD (100 oz) has a value of about $10 per 0.10 price move (commonly quoted as $1 per pip where a pip is $0.01, or $10 per "big pip" of $0.10). This calculator uses $10 per $0.10 move — enter your stop in $0.10 increments.

The formula is identical, but many traders cut risk to half size (e.g. 0.5%) right after getting funded and right before reaching a payout — the two points where a breach costs you the most. Some firms also add explicit per-trade risk caps on funded accounts.