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Position Size Calculator

Risk-based position sizing for any asset class. Enter your account size, the percent you're willing to risk, and your stop distance — the calculator gives you the exact position size in units, shares, or contracts.

What is position sizing?

Position sizing is the most important decision in any trade — more important than the entry price or the indicator that triggered the trade. The math is simple: position size = (account × risk%) ÷ stop distance. If you have a $10,000 account, you risk 1% per trade ($100), and your stop is $2 below entry on a stock — your position size is 50 shares. If the trade goes against you and hits the stop, your max loss is exactly $100. If it works, your upside depends on your target.

Risk percent guidelines

Risk per tradeFor whom10-loss drawdown
0.25%Brand new traders~2.5%
0.5%Conservative pros~5%
1%Standard retail~9.6%
2%Aggressive retail~18.3%
5%+Gamblers~40%

Drawdown column shows the percentage loss after 10 consecutive losing trades using risk-based sizing. The compounding makes 2% feel much worse than "20% gross" suggests.

Common questions

What is position sizing?

Choosing how many shares/contracts/lots to buy based on how much you're willing to lose if the trade fails. Standard model risks fixed percent (0.5%–2%) of account per trade.

What is the 1% rule in trading?

Limits loss on any single trade to 1% of total account. Position size adjusts based on stop distance. Foundation of retail risk management.

How do I calculate position size?

(Account × risk %) ÷ stop distance. The calculator above does this automatically.

Is 2% risk too much per trade?

Upper end of prudent. 10 consecutive 2% losses = 18% drawdown. Pros risk 0.5–1%. New traders start at 0.5% or lower.

Should I adjust position size after losses?

Yes automatically. Risk-based sizing scales to current equity. Prevents martingale on shrinking accounts.

Related tools

Chart with proper risk management

TradingView's order tool shows position size based on chart-drawn stops.

Download for Windows
Affiliate disclosure: Authorized TradingView affiliate. Calculator is for educational use. Trading involves substantial risk of loss.