Stock Share Quantity Reference Guide
Stock sizing uses the dollar difference between entry price and stop-loss price. Cash risk divided by that per-share risk gives the share quantity.
Use the stock calculator when you have a planned share entry price and a stop-loss price. The calculator first converts account balance and risk percentage into cash risk, then divides that amount by the entry-to-stop difference. A $25,000 account risking 1% has $250 of cash risk. If a stock entry is $50 and the stop is $47.50, the risk per share is $2.50 and the risk-based size is 100 shares.
The allocation cap is separate from stop-loss risk. It prevents the position value from consuming too much of the account even when the stop is tight. For example, 100 shares at $50 creates a $5,000 position value. If the account allocation limit is lower than that, the calculator caps the share count before showing the final result.
This page is designed for share quantity, not forex lots or futures contracts. Use the futures calculator when the instrument is quoted by tick size and tick value. Use the generic calculator only after you already know the dollar risk per unit.
Before placing a stock order, verify whether your broker supports fractional shares, whether the symbol is easy to borrow for short trades, and whether commissions, fees, extended-hours spreads or market gaps change the practical risk. The calculator does not know live liquidity or order execution quality.
These calculators are educational estimates. Spread, slippage, commission, fees and execution delay are excluded unless added manually.
Stock sizing checklist
- Confirm the entry and stop prices before changing the share quantity.
- Check whether the resulting position value fits account allocation limits.
- Round down if your broker requires whole shares.
- Recalculate after earnings gaps, halted sessions or major price changes.