Stock Position Size Calculator – Size Your Trades with Confidence

Use this stock position size calculator to determine the optimal number of shares to trade for stocks and ETFs. Enter your account balance, risk percentage, and stop-loss per share — the tool shows the exact number of shares to buy, your risk amount, and total cost. This stock risk management calculator helps you protect your capital and trade with discipline.

Stock Position Size Calculator
%
Number of Shares —
Risk Amount —
Total Cost —
Position Size (Value) —
Risk Per Share —
Commission —
⚠️ Illustrative only. Not financial advice. Please delete history timely, it may impact your browser performance.

History — Stock Position Size Calculator

# Time Balance Risk % Stop (per share) Stock Price Shares Risk Amount Action

Why Use This Stock Position Size Calculator

Proper position sizing is essential for risk management in stock trading. This stock position size calculator helps you:

  • 💰 Calculate Your Share Count — know exactly how many shares to buy.
  • 📊 Understand Your Risk — see exactly how much you’re risking.
  • 📉 Set Smart Stop-Losses — calculate position size based on your stop-loss.
  • 💵 Account for Commissions — include trading fees in your calculation.
  • 📈 Visualize Your Risk — see the breakdown of your trade.
  • 📜 Track Your History — save, review, and export past calculations.
  • 🔒 100% Private — all calculations run locally.

Stock Position Size Formula Used by This Tool

Risk Amount = Account Balance × (Risk% / 100)

Number of Shares = Risk Amount ÷ Stop-Loss Amount (per share)

Total Cost = Number of Shares × Stock Price

Position Value = Number of Shares × Stock Price

How to Use This Stock Position Size Calculator

  1. Select your account currency from the picker in the site header.
  2. Enter your account balance.
  3. Set your risk per trade percentage.
  4. Enter your stop-loss in dollars per share.
  5. Enter the stock price (optional — to see total cost).
  6. Enter the stock symbol (optional — for reference).
  7. Toggle commission on/off and enter the commission amount.
  8. View your results instantly — see the number of shares to buy and your risk amount.

Frequently Asked Questions

How is stock position size calculated?

Position size (shares) = Risk Amount ÷ Stop-Loss per Share. Risk Amount = Account Balance × (Risk% / 100).

What is the stop-loss per share?

The stop-loss per share is the dollar amount you’re willing to lose per share. If you buy at $50 and set a stop at $47.50, your stop-loss per share is $2.50.

Why is stock price optional?

The stock price is optional because the core calculation only needs the stop-loss per share and risk amount. The price is used to show the total cost and position value.

What is a good risk percentage for stocks?

Most traders risk 1-2% of their account balance per trade. This helps protect your capital during drawdowns.

Is my data stored anywhere?

No. All calculations run locally in your browser. History and presets are saved in your browser’s localStorage — nothing is sent to a server.