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Prop Firm Position Size Calculator
Enter your account size, the risk % you accept per trade, and your stop loss distance. The calculator instantly gives you the lot size and dollar amount at risk, so every trade stays consistent with your plan — no manual math, no signup.
How position size is calculated
The formula used to calculate lot size:
Lot Size = (Account Size × Risk%) / (Stop Loss in Pips × Pip Value)
Example: with a $10,000 account risking 1% per trade, you risk $100 per trade. With a 20-pip stop loss and a $10 pip value, lot size = 100 / (20 × 10) = 0.5 lot.
Frequently asked questions
What is position size?
Position size is the order size (lot size) calculated from your account balance, the risk percentage you accept per trade, and your stop loss distance, so every trade risks the same amount regardless of pair or stop loss width.
How do you calculate lot size?
Lot size = (account size × risk %) / (stop loss in pips × pip value). This tool calculates it automatically — just enter your account size, risk %, and stop loss.
Is 1% risk per trade safe for a prop firm challenge?
Most prop firms cap max daily loss and max drawdown around 4-10%. Risking 1% per trade is a common choice because it leaves room for several mistakes before hitting the drawdown limit, but always check the specific rules of the firm you're trading with.
How is pip value calculated if I don't know the exact figure?
This tool provides a default pip value per currency group (pairs ending in USD, JPY, GBP, etc.) from the dropdown, but the exact figure varies by broker and contract size — check and edit the pip value field to match your broker before trading live.
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