Position size calculator
Work out the right lot size for any forex pair from your balance, the risk you accept and your stop loss. Pip values for pairs quoted in another currency are converted for you.
The position size formula
Lots = (Balance × Risk %) ÷ (Stop loss in pips × Pip value per standard lot)
Worked example. Balance $10,000, risk 1% ($100), stop 25 pips on EURUSD in a USD account. A pip on one standard lot is worth $10, so the position is 100 ÷ (25 × 10) = 0.40 lots.
The calculator rounds down to the 0.01 lot step most brokers use, never up, and shows what you actually risk at the rounded size.
Why position size matters
Risking a fixed share of the account on each trade stops one bad run from doing lasting damage. At 1% risk, ten losses in a row cost about 10% of the account; at 5% risk, the same run costs about 40%.
An expert advisor can do this for you when it sizes each trade from a risk percentage instead of a fixed lot. Browse our expert advisors for MT5 and MT4.
Position size FAQ
How do I calculate lot size in forex?
Divide the amount you are willing to lose by the stop loss in pips times the pip value of one lot. The calculator does it for any pair and account currency.
What is one pip worth?
For a pair quoted in your account currency, one pip on a standard lot (100,000 units) is worth 10 units of that currency, such as $10 on EURUSD in a USD account. JPY pairs are the exception: a pip is the second decimal place, so one pip on a standard lot of USDJPY in a JPY account is worth 1,000 yen.
How much should I risk per trade?
Many traders cap risk at 0.5–2% of the account per trade, and prop firm traders often go lower to stay clear of daily loss limits.
Does it work for gold?
Gold uses a different contract size, so use the gold lot size calculator for XAUUSD.
Where do the exchange rates come from?
From the European Central Bank’s daily reference rates, loaded when the page opens. Your broker’s live price will differ slightly; open “Exchange rates” in the calculator to type your own.