Position Size Calculator
Calculate how many shares to trade based on your account size, risk tolerance, entry price and stop loss.
Calculate your position size
Enter your trade details below.
What is a Position Size Calculator?
A position size calculator helps traders determine how many shares they can trade while keeping the potential loss within a predefined percentage of their trading account.
Instead of choosing a position size based on intuition, traders can define how much of their account they are willing to risk and use their entry price and stop loss to calculate a position size.
How to Calculate Position Size
Position sizing starts with the amount of money you are prepared to lose if the trade reaches your stop loss.
The amount at risk is calculated using your account balance and selected risk percentage.
Risk per share is the absolute difference between your entry price and stop-loss price.
Position Size Example
Imagine a trader has a €10,000 account and decides to risk 1% on a trade. The maximum planned loss would therefore be €100.
If the entry price is €100 and the stop loss is €98, the risk per share is €2.
Dividing €100 by €2 gives a position size of 50 shares. At an entry price of €100, the total position value would be €5,000.
Why Position Sizing Matters
Position sizing is part of risk management. Using a consistent process can help traders understand how much capital is exposed if a trade moves against them.
A position size calculator does not predict whether a trade will be profitable. It simply helps calculate a position based on the risk parameters entered by the trader.
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Start Journaling FreeFrequently Asked Questions
What is position size in trading?
Position size is the number of shares or units a trader chooses to trade in a particular position.
How is position size calculated?
One method divides the amount a trader is willing to risk by the difference between the entry price and stop-loss price.
Does this calculator work for long and short trades?
Yes. The calculator uses the absolute difference between entry price and stop loss, so the same calculation can be used for long and short stock trades.
Does the calculator include trading fees?
No. The calculation does not currently include commissions, spreads, slippage, taxes or other trading costs.