Position Size Calculator
How many lots to trade so that your stop loss risks exactly the share of the account you intend.
- Money at risk
- 100.00 USD
- Position size
- 0.25 lots
- Units
- 25,000
- Value per pip on this position
- 2.50 USD
How it works
Position sizing is the one calculation that keeps an account alive. Decide the share of the account you will risk on the trade, place the stop where the trade idea is wrong, work out what one pip is worth per lot on that pair in your account currency, and the lot size follows. The size is an output, never an input.
The calculator converts pip value when the pair's quote currency differs from your account currency, using reference rates you can overwrite with today's price. Round the result down to your broker's step, usually 0.01 lots, and add a few pips to the stop distance if you are sizing for news or thin markets, to allow for slippage.
The formula
Lots = (Balance x Risk%) / Stop pips / Pip value per lot
Worked example
Balance 10,000 dollars, risk 1 percent, so 100 dollars at risk. Stop 40 pips on EUR/USD, where one pip on a standard lot is 10 dollars. 100 divided by 40 is 2.50 dollars per pip; 2.50 divided by 10 is 0.25 lots, or 25,000 euros.
Same account and risk on GBP/JPY with a 60-pip stop. One pip per lot is 1,000 yen, about 6.70 dollars. 100 divided by 60 is 1.67 dollars per pip; 1.67 divided by 6.70 is 0.25 lots again, but the stop is half as far again in pips, which is why the pip value conversion matters.
Frequently asked questions
What risk percentage should I use?
One percent of the account per trade is the conventional figure for a beginner and two percent is the upper limit most professionals recognise. Smaller during a drawdown or when unsure.
Why is the result different for the same stop on two pairs?
Because a pip is worth a different amount on each pair once converted into your account currency. The calculator does the conversion.
What if the lot size is below my broker's minimum?
The account is too small for that trade at that risk. Widen the risk only if you accept it, reduce the stop only if the chart allows, or trade on a demo until the account is larger.
Results are arithmetic on the figures you enter and reference exchange rates; check contract sizes and pip values against your broker's specification. General education, not advice.