Position Size Calculator

Updated 31 October 2026 · Written by Broker Atlas Guides Desk · Data checked by Broker Atlas Data Desk

Short answer

The percent-risk method sizes every trade so that hitting the stop loses the same share of your balance, often 1–2%. Position size = balance × risk % ÷ (stop in pips × pip value per lot). With $5,000, 1% risk and a 25-pip stop on EUR/USD, that's 0.20 lots. Set the stop from the chart first, then let the size follow.

The percent-risk method in four steps

Pick the stop from the chart, not from your budget: below the swing low for a buy, above the swing high for a sell, or wherever your idea is proved wrong.
Measure the distance in pips from entry to that stop.
Choose your risk per trade as a percentage of the account.
Let the calculator give the size. The size changes trade by trade; the risk stays the same.

The alternative, picking a lot size first and then placing a stop that “fits”, is how small accounts end up with stops too tight to survive normal moves. If you’d rather work from a fixed cash amount, use the lot size calculator.

How to use it

Balance (USD): your account balance, or equity if trades are already open (MT4/MT5 show both in the Trade tab).
Risk (%): the share of the balance you’ll lose if the stop is hit.
Stop loss (pips): entry to stop. On USD/JPY, 150.00 to 149.70 is 30 pips.
Pip value per lot (USD): $10 for EUR/USD and GBP/USD; 1,000 ÷ the rate for USD/JPY (≈ $6.67 at 150.00); $10 for gold, where this site counts $0.10 as a pip. The pip value calculator gives other cases.

The formula

Position size (lots) = balance × risk % ÷ (stop in pips × pip value per lot)

The line under the result shows the cash at risk: balance × risk %.

Worked examples

Example 1: EUR/USD. Balance $5,000, risk 1%, stop 25 pips, pip value $10. $5,000 × 1% = $50 at risk. 50 ÷ (25 × 10) = 0.20 lots.

Example 2: gold. Balance $3,000, risk 1.5%, stop $15 below entry (150 pips at $0.10 per pip), pip value $10. $3,000 × 1.5% = $45 at risk. 45 ÷ (150 × 10) = 0.03 lots. On a 100-oz contract, 0.03 lots loses $3 per $1 move, so a $15 move costs $45.

The calculator rounds to two decimals. If the exact figure ends in 5 or more in the third decimal it rounds up; type the lower step into MT4/MT5 to stay within your risk.

Why a fixed percentage

Losing trades in a row	Balance left at 1% risk	at 5% risk
5	95.1%	77.4%
10	90.4%	59.9%
20	81.8%	35.8%

Each row is (1 − risk)^n: because the size shrinks as the balance falls, losses slow down. With a fixed lot size they don’t. The figures are arithmetic, not a forecast; a run of losses is normal for any strategy.

Limits

Stops aren’t guaranteed. In a gap or around a release the fill can be worse than your stop. Consider standing aside before high-impact data (economic calendar).
Costs. Spread and commission sit on top of the stop distance (spread basics).
Margin and leverage. A tight stop can produce a size whose margin leaves little free margin. Check it with the margin calculator and the effective leverage calculator.
Correlated trades. Three trades on EUR/USD, GBP/USD and gold against the dollar can behave like one large trade. Count their combined risk.

More on sizing, daily loss limits and leverage in risk management with high leverage.

Frequently asked questions

What risk percentage should I use?

That's your decision, and we don't give personal advice. The point of the method is consistency: a small fixed percentage means a losing streak shrinks the account gradually rather than all at once.

Should I use balance or equity?

Either works if you're consistent. Equity (balance plus open profit or loss) is more conservative while other trades are running.

Why did my position size come out tiny?

Because the stop is wide or the account is small. That's the method working: a wide stop needs a small size to keep the same risk. If the result is below 0.01 lots, the trade is too big for the account.

Does this include spread and commission?

No. Add them to your stop distance or reduce the size slightly to keep total risk within your limit.