Position Size Calculator
Calculate how much capital to allocate per trade based on your risk tolerance.
Input Parameters
Enter your account details and trade setup
Total trading account balance
Percentage of account you are willing to risk
Position Details
Your calculated position breakdown
Enter your account size, risk %, entry price, and stop loss to calculate position size
How the Position Size Calculator Works
The formula for position sizing is:
Stop Distance % = ((Entry Price − Stop Loss) ÷ Entry Price) × 100
Position Size (units) = Risk Amount ÷ (Entry Price − Stop Loss)
Capital Required = Position Size × Entry Price
Variables: Account Size is your total trading capital. Risk % is the portion of your account you are willing to lose on this trade. Entry Price is your planned purchase price. Stop Loss Price is the price at which you will exit if the trade moves against you. Position Size is the number of units to buy.
How this calculator works
The Position Size Calculator uses a standard risk management formula: it first calculates your maximum acceptable loss (risk amount) as a percentage of your account, then divides that by the distance from entry to stop loss to determine how many units you can trade. The wider your stop, the fewer units you get — this naturally prevents oversized positions. All calculations are deterministic based purely on the values you enter. Results update live as you type, with no submit button required.
Understanding position sizing
Position sizing is one of the most overlooked yet critical components of trading risk management. Professional traders determine their position size before entering any trade based on a fixed risk percentage of their account, not on gut feeling or the size of a potential payout. The core principle is that no single trade should be large enough to significantly damage your portfolio. By tying position size to a fixed percentage risk, you automatically trade smaller when prices are volatile (wider stops) and larger when you can place tight stops near key support levels. This creates a consistent risk profile across all your trades regardless of market conditions. The 1% rule is a popular starting point — risking 1% of your account per trade means you would need 100 consecutive losing trades to lose everything, which is statistically unlikely with any half-decent strategy. Remember, position sizing does not predict profitability, it manages loss magnitude. This is educational context, not financial advice.