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Position Size Calculator
Position size is a function of risk, not conviction. Enter your account size, the percentage you're willing to risk, and your entry and stop — the calculator returns the exact position size that keeps your maximum loss fixed, regardless of how wide the stop is or how volatile the market gets.
How position sizing works
The formula: Position Size = (Account × Risk%) ÷ (Entry − Stop). Most blowups don't come from bad ideas — they come from good ideas sized recklessly. Fixing your dollar risk per trade does three things automatically: it keeps every loss survivable, it shrinks your size when stops must be wide (volatile conditions), and it lets you size up legitimately when your setup offers a tight, structure-based stop.
Pair this with a minimum 2:1 reward-to-risk and you can be wrong more often than right and still be profitable — check the math on our expectancy calculator.
Frequently asked questions
How do you calculate position size?
Position size = (account size × risk per trade %) ÷ distance between entry and stop loss. For example, with a $10,000 account risking 1% ($100) on a trade with entry at $100 and stop at $95, position size = $100 ÷ $5 = 20 units.
What percentage of my account should I risk per trade?
Professional traders typically risk 0.5–2% of their account per trade. At 1% risk you can lose 10 trades in a row and still have 90% of your capital. Risking more than 3% per trade puts you at serious risk of an unrecoverable drawdown.
Why does a wider stop loss mean a smaller position?
Because your dollar risk stays fixed. If your stop is twice as far from entry, you take half the position size — so a stop-out costs you the same amount either way. This automatically adjusts your size for volatility.
Should I size up when I feel confident about a trade?
No. Position size should be a function of risk, not conviction. The correct way to express higher conviction is through trade selection and a tighter, structure-based stop — which mathematically allows a larger size at the same fixed risk.
This calculator runs automatically inside LogYourTrade.
Every trade you plan gets sized from your risk constitution — with hard daily and weekly loss limits the app actually enforces. Stop calculating in a spreadsheet and start trading inside your process.