Position size calculator
Enter your balance, risk percent, entry and stop — instantly see how many shares to buy and how much you lose if the stop is hit.
Free · works without signing up
From numbers to practice
In the app you can try the trade in paper trading right away: a $10,000 virtual balance, stop-losses and a trading journal.
Signing up is free and takes a minute via Telegram.
What it calculates
Calculates how many shares to buy so that a single trade never loses more than a set percentage of your balance. The further away your stop-loss, the smaller the size — the money at risk stays the same.
Formula
Risk amount = Balance × Risk% Size = Risk amount ÷ |Entry − Stop|
Example
Given
- Balance — $1000
- Risk — 1%
- Entry price — $200
- Stop-loss — $196
- Risk amount: $1000 × 1% = $10 — the money you're willing to lose on this trade.
- Stop distance: $200 − $196 = $4 (2% of the entry price).
- Size: $10 ÷ $4 = 2.5 shares.
- Position value: 2.5 × $200 = $500 — half your balance is deployed...
- ...but if the stop hits you lose 2.5 × $4 = $10. Exactly 1%.
Result: You buy 2.5 shares. If the stop hits you lose $10 (1%) — no more.
Tip
Always run this calculator FIRST. Size is set by "how much am I willing to lose", not "how much money do I have". Risk is usually kept at 1–2%.
Frequently asked questions
- How is position size calculated?
- First the risk amount: balance × risk percent. Then it is divided by the distance between entry and stop. The result is the number of shares; if the stop is hit you lose exactly the risk amount.
- What percent of my balance should I risk per trade?
- Many traders follow the 1–2% rule, so that even several losing trades in a row do not seriously damage the balance.
- Does the calculator handle leverage or shorts?
- No — spot (buy) trades only; leverage and shorts are not covered.
Further reading
- Position size and risk/reward: the 2 questions before every tradeHow many shares to buy and whether the trade is worth it — work out both before you enter. Formulas, a worked example and the most common mistakes.
- Why you should trade on a demo account firstA demo account is a free practice ground: test your plan, find mistakes cheaply and build statistics. How to use it and where it differs from the real market.
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