Position Size Calculator
Calculate your position size based on account size, risk percentage and stop loss.
How it Works
Calculate Capital at Risk
Determines the maximum currency amount you are willing to lose on this specific trade. Usually kept under 1-2% of total capital.
Determine Invalidation Range
The absolute difference between entry price and stop loss price. In Forex this represents pips; in Futures it represents points.
Size Calculation
Computes the exact number of shares, contracts, or lots to buy or sell to ensure your maximum loss matches your predefined risk threshold.
Example: Stocks Long Trade
Suppose you have an account size of $10,000 and you wish to risk 1.0% on a long stock position.
You want to buy shares of a stock at $150.00 with a Stop Loss set at $145.00. The stop distance is $5.00 per share.
Your calculated position size will be 20 shares, exposing exactly $100.00 of risk. If price hits stop loss, you lose $100. If price reaches the 1:2 reward target of $160.00, you gain $200.
Risk Management Tips
The 1% Risk Rule
Limit your risk on any single trade to 1% or 2% of your account size. This protects your account from catastrophic drawdown streaks.
Always Use a Stop
Define your exit point before entering a trade. Never adjust your stop loss wider once the trade is active to avoid emotional decisions.
Skew Risk Reward
Aim for trades with at least a 1:2 or 1:3 reward-to-risk ratio. This means you can be wrong 60% of the time and still be net profitable.
Monitor Correlation
Be mindful of open positions in highly correlated assets (e.g., EURUSD and GBPUSD). Sizing should be reduced to avoid compounding risk.
Log and Audit
Document every trade, including sizing decisions and exit reasons. Reviewing past mistakes builds consistency and self-discipline.