FREE TRADING TOOL
Position size calculator
Risk-based position sizing divides the amount you are prepared to lose by the price distance between entry and stop. This version is for direct-price units such as shares or spot crypto—not forex lots, options contracts, or futures tick values.
Updated August 31, 2026 · Educational information onlyTHE FORMULA
Position size = (account size × risk %) ÷ |entry price − stop price|
The fractional result is mathematical size; the whole-unit result rounds down so price risk does not exceed the entered amount before costs. Fees, slippage, gaps, leverage, and contract multipliers are excluded.
WORKED EXAMPLE
See how the number is produced.
For a $25,000 account risking 0.5%, the risk amount is $125. With entry at $50 and stop at $48.75, risk per unit is $1.25, producing 100 whole units and $5,000 notional value.
HOW TO READ IT
Interpret the result with context.
- Whole-unit rounding down keeps planned price risk at or below the input before costs.
- The notional value shows capital exposure; it can exceed cash balance when leverage is used, but this tool does not assess margin rules.
- A stop is not guaranteed to fill at its exact price, so actual loss can be larger.
COMMON MISTAKES
Keep the inputs consistent.
- Using this direct-price formula for forex lots or futures/options contracts.
- Forgetting fees, slippage, gaps, or a contract multiplier.
- Rounding units up and unintentionally exceeding the risk amount.
- Treating account risk percentage as a recommendation rather than a personal input.
COMMON QUESTIONS
Position size calculator FAQ
Does this work for forex or futures?
No. Those instruments require pip value, contract multiplier, tick value, currency conversion, and broker-specific lot rules that this calculator deliberately does not model.
Why show fractional and whole units?
Some assets support fractional units while many shares or contracts do not. The whole-unit result rounds down rather than increasing planned price risk.