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Position Size Calculator for Trading
Find the right number of shares based on capital, risk, and stop-loss.
Position Size Calculator
Calculate the right number of shares based on your risk tolerance
Risk Amount
$10,000
Risk per Share
$20
Position Size
500 shares
Position Value
$250,000
Total Capital$500,000
100%
Position Value$250,000
50%
Max Risk Amount$10,000
Position sizing ensures you never risk more than a set percentage of your capital on a single trade. Enter your capital, risk tolerance, entry price, and stop-loss to find the right number of shares. Proper position sizing is fundamental to long-term trading survival and consistent risk management.
Frequently Asked Questions
What is position sizing in trading?
Position sizing determines how many shares or lots to buy in a single trade based on your total capital, risk tolerance per trade, entry price, and stop-loss level. It ensures no single losing trade wipes out a disproportionate amount of your capital.
What percentage of capital should I risk per trade?
Most professional traders risk 1–2% of their total capital per trade. For example, with 1% risk on your account, you would limit the maximum loss on any single trade to 1/100th of your total capital. This approach protects your capital through inevitable losing streaks.
How does stop-loss affect position size?
A wider stop-loss means fewer shares (to keep risk constant), while a tighter stop-loss allows more shares. Position size = Risk Amount ÷ (Entry Price − Stop-Loss Price). The calculator handles this automatically based on your inputs.