GBP/USD position size calculator

Decide the loss you accept and where the stop goes; the size follows. Risk $100 with a stop 50 pips away on GBP/USD and the size is 0.20 lot — because each pip on one lot is worth $10.00. The tool does this with your balance, risk percentage and stop.

Instrument1 lot = 100,000 GBP. One pip is 0.0001. Orders run from 0.01 to 20 lots.PriceOur last reading was 1.35171. Indicative — your platform is the price that fills.Account balanceUSDRisk per trade%Most professionals stay at or under 1–2%.Stop distancepips

0.20 lots

risking $100.00 of $10,000.00

Show the working +

1.00% of $10,000.00 = $100.00 you are willing to lose.
A pip is worth $10.00 per lot, so a 50 pip stop costs $500.00 per lot.
$100.00 ÷ $500.00 = 0.200 lots.
Rounded DOWN to 0.20 — rounding up would break the limit you just set.
That position controls $27,034.20 of GBP.

Reference prices in the text are round teaching numbers; the calculator prefills our last stored reading, indicative only. Contract sizes follow the standard conventions printed above the calculator; your account’s own specification is what applies. Nothing here is a recommendation.

The sum for GBP/USD

Lots = risk ÷ (stop distance × value per pip per lot). For GBP/USD: $100 ÷ (50 × $10.00) = 0.20 lot. 1 lot = 100,000 GBP. One pip is 0.0001.

The tool rounds down to the platform's lot step (0.01) and refuses to round up: if your risk budget implies less than 0.01 lot, no permitted size meets it, and it says so rather than quietly risking more.

The rule the sum enforces

The stop comes before the size. Traders who pick the size first and then look for a stop that "fits" end up with the stop where the size allows, not where the chart says. A $100 risk on GBP/USD is 0.20 lot at a 50 pips stop and half that at twice the distance — the risk stays the same, which is the point. The planned loss assumes the stop fills at its level; a gap through it costs more.

Common questions

How many lots of GBP/USD for $100 risk?: Depends on the stop. At 50 pips: 0.20 lot. Halve the stop distance and the size doubles; the dollar risk does not.
What percentage of my account should one trade risk?: Most guides say 1–2%; the tool defaults to 1%. The right number is the one that lets a run of ten losers happen without changing how you trade.

Same tool, other instruments

The numbers behind every symbol are on the contract specifications page; the forex cost guide adds spread, commission and swap together; and the market hours page says when it trades.