Example inputs are editable assumptions, not a published portfolio result.
Enter the amount available for this position
Use the same currency for capital, entry price and stop price. The risk percentage is the share of available capital you plan to lose if the stop fills at the entered price. It is not the share of capital allocated to the position.
Worked example: 50 units
With $10,000 available capital, 1% risk, a $100 entry and a $98 stop, the risk budget is $100 and the stop distance is $2. The result is 50 whole units, costing $5,000, with a planned stop loss of $100. The capital cap would allow 100 units, but the risk budget is the tighter limit.
Formula and capital cap
Risk budget = available capital × risk percentage / 100. Planned loss per unit = entry price minus stop price. Whole units = the smaller of floor(risk budget / stop distance) and floor(capital / entry price).
The capital cap assumes a fully paid long position with no leverage. If one unit exceeds your risk budget or available capital, the result is zero units; the calculator does not round up to force a trade.
Allow for uncertain stop fills
Planned loss assumes execution at the entered stop price. Gaps, illiquidity, fees and slippage can increase realized loss. A stop is not a guaranteed fill price.
This calculator sizes one long position. It does not model portfolio correlation, options contract multipliers, short-sale margin or fractional shares. Keep all prices and capital in the same currency.