Position Size Calculator
Work out the exact lot size so a losing trade only costs you the percentage of your account you choose. Proper position sizing is the #1 habit that keeps traders in the game. All math runs in your browser.
Why position sizing matters more than entries
Most new traders obsess over where to enter and ignore how much to trade — which is backwards. You can be right less than half the time and still grow your account if you cut losses small and let winners run. Position sizing is how you guarantee a single trade can’t do serious damage. Set a fixed risk per trade (most pros use 1–2%), and let this calculator convert that into the correct lot size for your stop.
The formula
Lots = (Account balance × Risk %) ÷ (Stop-loss in pips × Pip value per lot)
Example: a $5,000 account risking 1% ($50) on a trade with a 30-pip stop on EUR/USD (pip value ≈ $10/lot): 50 ÷ (30 × 10) = 0.17 lots. If the stop is hit, you lose about $50 — exactly 1% — no matter how the trade feels.
Frequently asked questions
What is a position size calculator?
It tells you how many lots to trade so that, if your stop-loss is hit, you only lose a fixed percentage of your account. You enter your balance, the percentage you’re willing to risk, and your stop-loss in pips; it returns the correct position size.
How much should I risk per trade?
Most professional traders risk 1–2% of their account per trade. Risking more means a losing streak can wipe out your capital quickly. The 1% rule means even ten losses in a row only draw your account down about 10%.
How is position size calculated?
Position size = (account balance × risk %) ÷ (stop-loss in pips × pip value per lot). The result is the number of lots that caps your loss at the chosen risk amount if the stop is hit.
Does position sizing work for gold and indices?
Yes — the same formula applies, but the pip/point value differs by instrument. Enter the correct value-per-lot for the instrument you’re trading; this calculator lets you adjust it.
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Pip values are indicative and depend on the instrument’s current price and your account currency. Not investment advice. Trading carries risk.
