Calculate how many shares to buy based on your account size, risk percentage and stop loss.
Risk Amount
Shares
Position Value
Risk per Share
Quick Summary
A stock position size calculator helps traders and investors determine how many shares they should buy based on how much money they are willing to risk on a trade. Instead of guessing position size, you calculate it using your account balance, risk percentage, entry price and stop loss price.
Position sizing is one of the most important parts of risk management. Even if your stock analysis is good, buying too many shares can expose your account to large losses. By using a fixed percentage risk model, traders can stay consistent and protect their capital over the long term.
The basic formula is:
Where:
Many traders risk between 0.5% and 2% of their account on a single stock trade. Lower risk usually helps reduce drawdowns and makes the trading system more stable.
Yes. This calculator works well for swing trading, breakout trading and many other stock trading strategies that use a defined stop loss.
If the stop loss is very tight, the formula may produce a large share size. In real trading, you should also check whether the total position value fits within your available capital and broker rules.