Position Size Calculator
Size a position from account balance, per-trade risk percentage and stop distance so the maximum loss stays controlled.
Results
Fill in the inputs and click Calculate.
- Max Loss
- –
- Quantity
- –
- Position Value
- –
Risk disclaimer
This calculator provides estimates for informational purposes only and is not financial advice. Actual fills, fees and slippage may make real losses larger.
What is a position size calculator?
Decide “how much you can lose” (balance × risk %), then derive quantity from the stop distance (entry minus stop): Quantity = Risk Amount ÷ Loss Per Unit.
This uses a long-side model; short positions with a stop above entry use the same distance formula. Slippage and fees are not counted in the loss.
How to use
- Enter account balance and per-trade risk % (e.g. 1 = 1%).
- Enter the planned entry and stop price.
- Click Calculate to see max loss, suggested quantity and position value.
Formula
- Risk Amount = Balance × Risk %
- Loss Per Unit = |Entry − Stop|
- Quantity = Risk Amount ÷ Loss Per Unit
- Position Value = Quantity × Entry Price
Example
Balance 10,000, risk 1% (100), entry 20,000 and stop 19,500 (distance 500): quantity = 100 ÷ 500 = 0.2, position value = 4,000.
Halving risk to 0.5% gives a quantity of 0.1 for the same stop.
FAQ
What risk % should I use?
A common range is 0.5%–2% per trade. Lower percentages keep drawdowns manageable after losing streaks.
Are fees and slippage included?
No. To be more conservative, widen the stop or lower the risk percentage to absorb them.
Can I use this for shorts?
Yes. For shorts the stop sits above entry; |entry − stop| still gives the correct distance.