Forex position size calculator
In forex, the same risk can mean very different lot sizes depending on your stop and the pair you trade. Enter your account balance, the percentage you are willing to lose, your stop in pips and the pair and price, and this calculator gives you the number of lots that keeps the loss at your limit. It also shows how the size changes with wider or tighter stops.
Lots at different risk levels
Your stop and pair at other risk percentages.
Wider stop, smaller position
The lots that keep your risk the same for different stop distances. A wider stop is fine as long as the position shrinks to match.
| Stop | Lots | Units | Pip value | Loss if stopped out |
|---|
How the lot size is worked out
You fix the money at risk and the stop distance. The calculator finds what one pip is worth on one standard lot of your pair in dollars, then works out how many lots make the stop cost exactly your risk.
Money at risk
A share of your balance.
risk = balance × risk %
Pip value per standard lot
Contract size times pip size, converted to dollars: as is for USD-quoted pairs, divided by the price for USD-based pairs, times the quote rate for crosses.
EUR/USD: 100,000 × 0.0001 = $10
Lots
Risk divided by what the stop costs on one lot, rounded down to 0.01.
lots = risk ÷ (stop pips × pip value per lot)
Actual risk
The rounded lot size times the stop, which is at or just under your limit.
actual risk = lots × stop × pip value per lot
Forex position size questions
How do I calculate position size in forex?
Divide the money you are willing to risk by your stop distance in pips times the value of one pip 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, which is 0.8 lots.
Why does the pair matter?
Because pip values differ. A pip on a standard lot of EUR/USD is always $10, but on USD/JPY it depends on the yen rate and on crosses like EUR/GBP it depends on the pound's rate against the dollar. The calculator converts each one to dollars before sizing the trade.
Why is my position rounded down?
Most brokers let you trade in steps of 0.01 lots, so the calculator rounds down to the nearest step. Rounding down keeps the risk at or below your limit rather than slightly above it.
How much should I risk per trade in forex?
Many traders risk 0.5 to 2 percent of the account per trade. Forex moves fast and leverage makes large positions easy to open, so a fixed percentage is the simplest protection against a run of losses.
Should my stop be in pips or in price?
Either works; the calculator uses pips because that is how most forex traders think about stops. Set the stop where the chart says the trade is wrong, then let the position size fit the stop, not the other way round.
Does spread affect position size?
The spread adds to your loss if the stop is hit, so include it in the stop distance for short-term trades. A 2-pip spread on a 10-pip stop is a fifth of your risk.