Lot Size Calculator
Calculate the correct position size for any prop firm challenge. Never risk more than you plan.
Position Size Calculator
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Risk Presets
Click a preset to auto-fill risk percentage:
Risk by Account Size
Calculate a lot size to see results across common account sizes.
Prop Firm Risk Rules
FTMO — Recommended max risk1% per trade
Daily loss limit (most firms)5% of balance
Max drawdown (most firms)10% of balance
How Lot Size is Calculated
The Formula
Lot Size = Risk Amount ÷ (Stop Loss Pips × Pip Value)
Where Risk Amount = Account Balance × (Risk% ÷ 100). For a $10,000 account risking 1% with a 20-pip stop loss on EUR/USD: Risk Amount = $100, Lot Size = 100 ÷ (20 × $10) = 0.50 lots.
Why This Matters for Prop Firms
Most prop firm challenges fail not from bad trading — but from oversizing. A single 2% loss on an oversized trade can eat into your daily drawdown limit before you've had a chance to recover.
Keeping risk at 0.5–1% per trade gives you room to have losing trades without triggering limits.