Position Size Calculator
Calculate the exact lot size for any trade based on your account size, risk percentage, and stop loss distance. Built for prop traders.
Recommended: 0.5-2% for prop accounts
$10 for standard lot EUR/USD, $1 for mini
Position Size
Risk: $1,000 per trade (1%)
Standard Lots
4.00
100,000 units
Mini Lots
40.0
10,000 units
Micro Lots
400
1,000 units
10% Max Drawdown
10 losses
consecutive losing trades before breach
5% Daily Limit
5 losses
consecutive losing trades before daily breach
Formula
Position Size = (Account x Risk%) / (Stop Loss Pips x Pip Value)
= ($100,000 x 1%) / (25 x $10) = 4.00 lots
How to Use This Position Size Calculator
Enter your account size, the percentage you want to risk on a single trade, and your planned stop loss distance in pips (forex) or ticks (futures). The calculator instantly shows you the exact lot size or number of contracts to trade.
Why Position Sizing Matters for Prop Traders
Over-leveraging is the number one reason traders fail prop firm challenges. By calculating the correct position size before every trade, you ensure that no single loss can consume too much of your drawdown allowance. Professional prop traders risk between 0.5% and 2% per trade — this calculator makes it easy to stay within those limits.