Position Size Calculator
position-size• Get the number of shares to buy from account size, risk %, entry, and stop-loss. • A money-management tool that caps your loss per trade at a fixed share of the account.
Total balance in your trading account
Share of the account you can lose on one trade (usually 1–2%)
Position size
200 shares
What is position sizing?
Position sizing is a money-management method: instead of "how much to buy", you fix the amount you lose if the stop is hit to a set share of your account. The risk amount is divided by the per-share risk (the gap between entry and stop) to get the quantity.
Formula: shares = (account × risk %) ÷ per-share risk. Per-share risk is the difference between entry and stop. Example: account 10,000, risk 1% (100), entry 100, stop 95 → per-share risk 5 → 20 shares. The quantity is rounded down so you never exceed your risk.
Keeping risk at 1–2% means a losing streak will not shake your account much. Longs and shorts are calculated the same way (absolute difference). Fees and slippage are not included — this is a theoretical figure.
Frequently asked questions
How wide should my stop-loss be?
There is no fixed answer. Set the stop where you would admit the trade idea was wrong, then let the quantity follow — that is the order this calculator assumes. A tighter stop gives you more shares and a wider stop fewer, but the money at risk stays the same share of your account.
What percentage of my account should I risk per trade?
1–2% is the common benchmark. At 1%, ten losses in a row shrink the account by only about 10%, leaving room to recover. Risk 10% per trade and five bad calls halve your capital, which is very hard to earn back. The less proven your strategy — and the larger your account — the lower that percentage should be.
The position value came out larger than my whole account.
That happens when the stop is very tight: dividing the risk amount by a tiny per-share risk produces a huge quantity. The tool flags it because the trade would require leverage or margin. Widen the stop or lower the risk percentage until the position fits your account.
Are fees and taxes included?
No. The calculator is a theoretical figure based only on the gap between entry and stop, so commissions, transaction taxes and slippage are excluded. Your real loss when the stop is hit will therefore be a little larger than the risk amount shown. In high-cost markets, or if you trade often, set the risk percentage lower from the start.
Does it work for leveraged or futures positions?
The formula is the same, but put your actual capital in the account field, not the margin posted. Using margin as the account figure multiplies the risk you are really taking. The higher the leverage, the more likely the liquidation price sits in front of your stop, so check where both prices fall before you send the order.
Can I trade exactly on these numbers?
Treat them as a reference. The calculation assumes you fill exactly at the stop price, but in a gap down or a thinly traded name you may fill well below it and lose more than shown. This tool is not investment advice — the final decision and its consequences are yours.