Forex Position Size Calculator
Size a forex trade to a fixed money risk: enter your account, risk percentage and stop-loss in pips to get the exact units and lots to trade.
How it works
Position size (units) = (account × risk%) ÷ (stop-loss in pips × pip size) · Lots = units ÷ 100,000
Fixed-fractional sizing keeps the money you can lose constant no matter how wide your stop is. First turn your risk percentage into a dollar amount, then divide by the loss per unit — the stop distance in pips times the pip size. A wider stop means fewer units for the same dollar risk, which is exactly how disciplined traders avoid blowing up on a single trade.
Worked example
With a $10,000 account, 1% risk and a 20-pip stop on a 0.0001-pip pair: risk is $100, loss per unit is 20 × 0.0001 = 0.002, so position size is 100 ÷ 0.002 = 50,000 units (0.5 standard lots).
Frequently asked questions
Why size to a percentage instead of a fixed lot?
Risking a fixed fraction of your account means each loss is proportional to your balance, so a losing streak shrinks your position sizes automatically and a growing account scales them up — the core of survivable risk management.
What risk percentage should I use?
Many traders cap risk at 1–2% of the account per trade. This calculator lets you set any figure, but larger percentages raise the chance of a deep drawdown from a run of losses.
Does this account for the pip value in my currency?
It assumes the pip value is in your account currency. If the quote currency differs, first find the pip value with the pip value calculator and adjust your stop-loss risk accordingly.
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Educational estimate, not investment advice. Trading forex, futures and options carries substantial risk of loss.