Position size calculator
Enter your account balance, the percentage you are willing to risk, your entry and your stop. The calculator returns the position size that loses exactly that amount if your stop is hit — the same size on every trade, whatever the market.
Log the trade with this stop in Alpha Charts and every result is measured in R automatically. Start free →
How the position size calculator works
- Risk amount
- Account balance × Risk %
- Stop distance
- |Entry price − Stop price|
- Position size
- Risk amount ÷ Stop distance
Step by step
- Enter your account balance in your account currency.
- Choose the percentage of the account you will risk — many traders use 0.5% to 2%.
- Enter your planned entry price and the price where your stop loss sits.
- Use the position size shown. For forex lots or futures contracts, divide by the units per lot or contract.
Questions about the position size calculator
What percentage should I risk per trade?
This is a personal decision based on your strategy and drawdown tolerance. Many traders keep risk between 0.5% and 2% per trade so that a losing streak does not cause a large drawdown. This calculator is not financial advice.
Does the calculator work for forex?
Yes. The result is in units of the base currency. Divide by 100,000 for standard lots, 10,000 for mini lots or 1,000 for micro lots. For non-USD quote currencies, convert the stop distance to your account currency first.
Why size by stop distance instead of a fixed number of shares?
A fixed share or lot count risks a different amount on every trade, depending on how far away the stop is. Sizing by stop distance keeps the loss at your stop constant, which makes your results comparable in R.
Related guides and journals
More free calculators
Guides
- Position Sizing Calculator: The Complete Guide for Traders
- Risk Management: The Foundation of Consistent Profitability
- Risk Management Strategies Every Day Trader Must Know
Trading journals
Stop calculating by hand. Journal it.
Alpha Charts measures every trade in R and tracks win rate and expectancy for each setup automatically.
Calculators are provided for educational purposes and are not financial advice. Results exclude fees, slippage and currency conversion.