Forex position size calculator
In forex, one risk budget can mean very different lot sizes depending on the pair and how far away the stop is. Enter the account balance, the percentage you will risk, the stop in pips and the pair and price, and you get the lot size that holds the loss to your limit. You can also see how the size changes as the stop widens or tightens.
Lot size at each risk level
Your pair and stop at other risk percentages.
A wider stop means a smaller trade
The lots that keep risk constant across different stop distances. A wide stop is fine as long as the position shrinks with it.
| Stop | Lots | Units | Pip value | Loss if stopped out |
|---|
How the number of lots is found
You set the money at risk and the stop distance. The calculator works out what a pip is worth on one standard lot of your pair in dollars, then how many lots make the stop cost exactly your risk.
Money at risk
A percentage of your balance.
risk = balance × risk %
Pip value per standard lot
Contract size times pip size in dollars: unchanged for USD-quoted pairs, divided by price for USD-based pairs, multiplied by the quote rate for crosses.
EUR/USD: 100,000 × 0.0001 = $10
Lots
Risk divided by the stop's cost on one lot, rounded down to 0.01.
lots = risk ÷ (stop pips × pip value per lot)
Real risk
The rounded lot size times the stop, which lands at or just below your limit.
actual risk = lots × stop × pip value per lot
Forex position sizing FAQ
How is a forex position size calculated?
Take the money you will risk and divide it by the stop in pips times the pip value per lot. Risking $200 with a 25-pip stop on EUR/USD, where a standard lot pays $10 a pip, gives 200 divided by 250: 0.8 lots.
Why does the currency pair change the answer?
Because pip values are different. A standard-lot pip on EUR/USD is always $10, but on USD/JPY it depends on the yen rate, and on crosses like EUR/GBP on the pound's dollar rate. The calculator converts each to dollars before sizing.
Why is the lot size rounded down?
Most brokers trade in steps of 0.01 lots. Rounding down to the nearest step keeps your risk at or below the limit instead of just over it.
What percentage should a forex trade risk?
Many traders use 0.5 to 2 percent of the account. Currency prices move quickly and leverage makes big positions easy to open, so a fixed percentage is the simplest defence against a losing streak.
Should I set my stop in pips or as a price?
Either works; pips are used here because most forex traders think in them. Put the stop where the chart says the idea is wrong, then size the trade to fit that stop rather than the other way round.
Does the spread matter for sizing?
Yes. The spread adds to your loss when the stop is hit, so on short-term trades include it in the stop distance. On a 10-pip stop, a 2-pip spread eats a fifth of your risk.