Position Size Calculator
How much should you risk on this trade?
Enter your account size, risk tolerance, and stop loss to calculate exact position size, risk/reward ratio, and expected value per trade.
A position size calculator is an essential risk management tool that determines exactly how many shares, contracts, or lots to trade based on your account balance, risk percentage, and stop loss distance. Use it as a forex position size calculator, a crypto position size calculator, or a position size calculator stocks and futures model — the formula is the same, only the contract specs change. By adjusting your sizing to match your risk profile, you ensure that no single losing trade can catastrophically damage your capital or trigger emotional trading behaviors.
Position Size = (Account Balance × Risk %) ÷ (Entry Price – Stop Loss)
How the Formula Works
A position size calculator is an essential risk management tool that determines exactly how many shares, contracts, or lots to trade based on your account balance, risk percentage, and stop loss distance. Use it as a forex position size calculator, a crypto position size calculator, or a position size calculator stocks and futures model — the formula is the same, only the contract specs change. By adjusting your sizing to match your risk profile, you ensure that no single losing trade can catastrophically damage your capital or trigger emotional trading behaviors.
Formula Expression
Example Calculation
"If you have a $10,000 account, risk 1% ($100), enter a stock at $50 with a stop loss at $48, your position size is: $100 / ($50 - $48) = 50 shares."
How to Use This Position Size Calculator
Enter Your Account Size
Input the total capital in your trading account. Use your actual account balance for the most accurate results. This balance acts as the mathematical baseline for all percentage-based risk parameters in the calculation process.
Set Your Risk Per Trade
Choose how much of your account you are willing to risk on this single trade. Most professional traders risk between 0.5% and 2% per trade. Higher risk values expose your portfolio to the risk of ruin during a typical statistical drawdown.
Enter Trade Prices
Input your entry price, stop loss, and take profit targets. The calculator will determine position size and show your full risk/reward profile. These values define the structural boundaries of your setup on the price chart.
Add Your Strategy Stats
Enter your historical win rate to see expected value per trade. A positive expected value confirms your edge is mathematically viable over a large sample of executions, ensuring that you only deploy capital when the math is in your favor.
Position Sizing Strategies Compared
See how mathematically calculated position sizing compares to other common approach types.
| Feature | Dynamic Position SizingBest | Fixed Dollar Risk | No Risk Control (Flat Lots) |
|---|---|---|---|
| Adapts to Stop Loss Distance | |||
| Protects Against Large Volatility | |||
| Risk of Ruin during Drawdown | Extremely Low | Low | High |
| Compounding Efficiency | Maximum | Moderate | Inefficient |
Position Size Calculator — Frequently Asked Questions
- A position size calculator forex tool works by taking your account size, desired risk percentage, and stop loss distance in pips. The calculator automatically converts the pip value based on the currency pair you are trading and your account base currency. It then outputs the exact trade size in standard lots, mini lots, or micro lots, saving you from complex manual pip-value calculations during active market sessions.
See how your math plays out in real trades
Import your trades into TradeZully to see if your execution matches the calculator. Real data, automatic sync, no spreadsheets.
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