How many shares should you actually buy?
Most blown accounts are not bad calls, they are bad size. Enter your account, the percent you are willing to risk, and your stop, and this tells you the exact number of shares that keeps a loss survivable.
Position Size Calculator
Size is the risk decision, not the entry
Traders obsess over where to get in and barely think about how much to get in with, which is backwards. Your entry decides whether you are right; your size decides whether being wrong is survivable. A fixed-percent rule ties your share count to your stop distance, so a wider stop automatically means fewer shares and the dollar risk stays constant. That single habit is what separates a bad day from a blown account.
Why one percent is the common default
Risking one percent of your account per trade means it takes a long, deliberate losing streak to do real damage, which buys you time to fix what is wrong. Risk five percent and a normal run of five or six losers, something every strategy produces, can cut your account in half. The calculator lets you test both so the trade-off stops being abstract and becomes a number you can see.
Frequently asked questions
Most disciplined traders risk between 0.5% and 2% of account per trade, with 1% a common default. The right figure keeps any single loss, and a normal losing streak, from doing damage you cannot recover from calmly.
Divide the dollars you are willing to risk, your account times your risk percent, by your stop distance per share, your entry minus your stop. The result is the number of shares that caps your loss at that dollar amount.
Yes. A wider stop should mean fewer shares and a tighter stop more, so your dollar risk stays constant regardless of the setup. Keeping size fixed while stop distance moves is how traders accidentally take oversized risk.
See whether your real sizing matches your rules
TraderLog imports every trade and shows where your actual position sizes drift from your plan, especially after losses when discipline slips most. Start with a 14-day free trial.