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Size your position.Protect your account.

Enter balance, risk % and stop loss to get the correct lot size for any pair instantly.

30+Pairs
8Currencies
$0Cost
100%Free
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Position Size Calculator
Know your lot size
Lot Size
standard lots
Units
contract units
Dollar Risk
max loss at stop
Pip Value
per pip / 1 lot
Risk %:
→ 30 pips
⚠ Prop firm rules: Never risk more than 0.5–1% per trade on challenges. A $100k account with 5% daily limit gives only $5,000 buffer.
Position Size Calculator 1% Risk Rule Prop Firm Safe Know Your Lot Size Free Tool No Signup Required Position Size Calculator 1% Risk Rule Prop Firm Safe Know Your Lot Size Free Tool No Signup Required
How it works
The Formula
// Position Size Formula
// Lot size from balance & risk
LotSize =
  (balance × risk_pct)
  ÷ (stop_pips × pip_value)

// Pip value in account currency
pip_value = pip_size × contract
  ÷ quote_rate
// Examples
// $10k · 1% risk · 20 pip stop · EUR/USD
Dollar Risk = $10,000 × 1% = $100
Pip Value = $10/lot × 20 = $200/lot
Lot Size = $100 ÷ $200 = 0.50 lots

// $50k · 0.5% risk · 30 pip stop
Dollar Risk = $250
Lot Size = $250 ÷ ($10 × 30) = 0.83 lots
Knowledge
Common Questions
What risk % should I use per trade? +
Professional traders risk 0.5–2% per trade. For prop firm challenges, keep it at 0.5–1% to protect against hitting the daily drawdown limit with a losing streak.
How does stop loss distance affect position size? +
Wider stop = smaller lot size. Tighter stop = larger lot size. The dollar risk stays the same (e.g., $100) but distributes across more or fewer pips.
What if I trade on a non-USD account? +
Select your account currency in the dropdown. The calculator automatically converts pip values to your account currency so the result is always accurate.
Is this calculator accurate for metals and indices? +
Yes. For Gold (XAUUSD), Silver (XAGUSD), NAS100 and other instruments the contract sizes and pip values are factored in automatically.

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