Markets
Position size (lot size) calculator
How many lots to trade so the computed loss at your stop stays within the amount you choose to risk, for forex pairs and gold, with the formula.
Position size
Fill in every field to see the position size.
Fill in every field to see the position size.
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How it is calculated
The calculator first turns your risk into an amount: balance × risk % ÷ 100. It then works out what one pip is worth for one lot, which is the pip size × the contract size, converted into your account currency when the pair is not quoted in it.
The position size is the amount at risk divided by the stop distance in pips times that pip value. It is rounded down to 0.01 lot, so the loss the calculator works out at your stop, at the price or rate you entered, never exceeds the amount you chose.
Worked example (synthetic numbers)
A USD account with a balance of 10,000, a risk of 1 % and a 25-pip stop on EUR/USD (contract size 100,000, pip size 0.0001).
With 0.40 lots, a 25-pip move against the position loses about 100.00 USD, the 1 % chosen, before spread, commission and slippage, which the calculator does not include. A wider stop at the same risk gives a smaller position.