Position size calculator
Position size is how many lots you trade. Work it out from the money you are willing to lose and the distance to your stop loss, never from how confident you feel. Enter three numbers below and the lot size comes out the other end.
US dollar is the quote currency. Calculations assume a US dollar account.
Your position size
0.20
lots (20,000 units)
You are risking
$50.00
Value of one pip
$2.00
Loss if stop is hit
$50.00
Rounded down to the nearest 0.01 lots, so the real loss stays at or just under your chosen risk. Spread, commission and overnight swap are not included.
The formula, in one line
Lots = risk amount ÷ (stop loss in pips × pip value per lot)
Say you have a $5,000 account and you are willing to risk 1%, so $50. Your stop is 25 pips away on EUR/USD, where one pip is worth $10 per standard lot. That gives $50 ÷ (25 × $10) = 0.20 lots. If the stop is hit you lose $50, which is exactly what you signed up for.
Why the pair matters
One pip is not worth the same everywhere. On pairs quoted in US dollars, one pip on a standard lot is exactly $10. On yen pairs a pip is 0.01 rather than 0.0001, so the value depends on the current USD/JPY rate. That is why the calculator asks which kind of pair you are trading instead of assuming.
Common questions
QHow do you calculate position size in forex?
Divide the money you are willing to lose by your stop loss distance multiplied by the value of one pip per lot. Risking $50 with a 25 pip stop on EUR/USD, where one pip is worth $10 per standard lot, gives 50 divided by (25 x 10), which is 0.20 lots.
QWhat percentage should I risk per trade?
Most educational sources suggest keeping risk per trade small, commonly 1% or less of the account while you are learning. The point is survival: at 1% risk, ten losing trades in a row costs about a tenth of the account, while at 10% risk the same run would be close to fatal.
QDoes the calculator include spread and commission?
No. It sizes the position from your stop loss distance only. Spread, commission and overnight swap are extra costs on top, so your real loss on a stopped-out trade will be slightly larger than the figure shown.
QWhy is my result smaller than 0.01 lots?
Your risk amount is too small for your stop distance. Most brokers cannot trade below 0.01 lots, so you either need a tighter stop, a larger account, or to accept that this particular trade is not sizeable for you yet.
Risk warning. This calculator is an educational tool, not financial advice. It does not account for spread, commission, swap or slippage, and a stop loss is not guaranteed to fill at your exact price during fast markets or weekend gaps. Always confirm contract sizes and costs with your broker.