Position size calculator
How many shares fit inside the risk you set
Enter account size, the percentage you are willing to risk, your entry and your stop. Get the share count and dollar risk that combination implies.
- Shares
- 41
- Dollar risk
- $250
- Risk per share
- $6
- Position value
- $4,100
What the inputs mean
- Account size
- Total capital the risk percentage is measured against.
- Risk per trade
- Share of the account you accept losing if the stop trades.
- Entry
- The price you expect to pay.
- Stop
- The price that invalidates the idea.
Formula
Worked example
$25,000 account, 1% risk, $100 entry, $94 stop → $250 of risk ÷ $6 per share = 41 shares, a $4,100 position.
Questions people ask
Why does a wider stop mean fewer shares?
Dollar risk is fixed by the account and the risk percentage. Widening the stop raises the loss per share, so the share count has to fall to keep total risk unchanged.
Should risk per trade change with volatility?
The percentage usually stays fixed; volatility shows up through the stop distance, which automatically shrinks the position in faster-moving names.
Limitations
Every result here is arithmetic on the numbers you enter. It carries no view on any specific security, assumes returns are steady when real returns are not, and ignores taxes, slippage and commissions. Use it to size and sanity-check, not to forecast.
Now run it on a real ticker
Score any name free, then bring the number back here.
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Understand the inputs
Autonium publishes research, not recommendations. Scores, factors and written reads describe historical and current data and are not buy or sell advice. Not financial advice. Market data is refreshed on a schedule and may lag. See our methodology and disclosures.