GBP/USD lot size calculator
Work out how many lots to trade on GBP/USD so hitting your stop loss costs exactly the amount you chose to risk.
Exchange rates as of 2026-09-30 15:59 UTC, refreshed hourly.
How the GBP/USD lot size is calculated
One standard lot of GBP/USD is 100,000 GBP, and one pip is a 0.0001 move in price, so a pip on one lot is worth 10 USD. For a USD account that is $10 per pip.
Lot size = (balance × risk %) ÷ (stop loss in pips × pip value per lot)
Example: a $10,000 account risking 1% with a 20 pip stop risks $100. $100 ÷ (20 × $10) = 0.50 lots.
Why does my lot size look wrong?
- Account currency. A pip is worth a different amount in EUR, GBP or JPY. Pick the currency your account is held in.
- Pips vs points. Most platforms show prices to 5 decimals (3 on yen pairs). The last digit is a point: 10 points = 1 pip.
- Rounding. Results round down to 0.01 lots so you never risk more than you set.
Sizing across several accounts?
The Forexizer Calculator app saves each account’s balance, currency, risk and contract sizes, then sizes one trade for every account at once. No retyping, no looking up specs.
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