Most traders spend their energy on entries. Yet two traders with the same entry signal can get very different results depending on how much they trade and where they put the stop. Position sizing with an ATR-based stop is a simple, widely used method that ties both decisions to current market volatility. This guide walks through the calculation step by step, with worked examples for gold (XAUUSD) and a forex pair.
What ATR measures
The Average True Range (ATR), introduced by J. Welles Wilder, measures how much an instrument typically moves per bar. It does not tell you direction — only the size of recent movement.
For each bar, the true range is the largest of:
- the current high minus the current low,
- the distance from the previous close to the current high, and
- the distance from the previous close to the current low.
ATR is a smoothed average of the true range over a set number of bars — 14 is the common default. Both TradingView and MT4/MT5 include ATR as a built-in indicator, and its value is shown in the instrument's price units (for example US dollars per ounce on XAUUSD, or a price difference such as 0.0060 on EURUSD).
Why base your stop on ATR?
A fixed stop — say, always 50 pips or always $5 on gold — ignores the fact that volatility changes. In a quiet market, a fixed stop may be far wider than necessary; in a fast market, the same stop may sit inside normal noise and get hit by ordinary fluctuations.
An ATR stop scales with conditions: wider when the market is moving a lot, tighter when it is calm. A common approach is to place the stop a multiple of ATR away from the entry:
Stop distance = ATR × multiplier
Multipliers such as 1, 1.5 or 2 are often used as starting points, but there is no universally "correct" value. It depends on your timeframe, strategy and how much room your setup needs. Treat the multiplier as a rule you test, not a number to copy.
The position sizing formula
Once you know the stop distance, position sizing answers one question: how large can this position be so that, if the stop is hit, I lose only the amount I planned to risk?
- Risk amount = account balance × risk per trade (%).
- Stop distance = ATR × multiplier (in price units).
- Loss per 1 lot at the stop = stop distance × value of a 1-unit price move per lot.
- Position size (lots) = risk amount ÷ loss per 1 lot at the stop.
Then round down to your broker's lot step. Rounding up quietly increases your risk.
The percentage you risk per trade is a personal decision. Many educational sources discuss keeping it small, because a series of losses is a normal part of trading. The examples below use 1% purely to illustrate the arithmetic — not as a recommendation.
Worked example 1: gold (XAUUSD)
All numbers here are hypothetical and chosen to make the arithmetic clear.
- Account balance: $10,000 · risk per trade: 1% → risk amount $100
- ATR(14) on your chosen timeframe: $4.00
- Multiplier: 1.5 → stop distance $6.00
- Contract size: at many brokers, 1 standard lot of XAUUSD = 100 ounces, so a $1.00 move = $100 per lot. Check your broker's contract specification — some use different contract sizes.
Loss per 1 lot at the stop = $6.00 × $100 = $600.
Position size = $100 ÷ $600 = 0.1667 lots → round down to 0.16 lots.
If the stop is hit, the loss is about 0.16 × $600 = $96, before spread, commission, swap and any slippage.
Worked example 2: EURUSD
- Account balance: $10,000 · risk per trade: 1% → risk amount $100
- ATR(14) on the daily chart: 0.0060 (60 pips)
- Multiplier: 1 → stop distance 60 pips
- Pip value: for a standard lot (100,000 units) of EURUSD in a USD account, 1 pip ≈ $10.
Loss per 1 lot at the stop = 60 × $10 = $600.
Position size = $100 ÷ $600 = 0.1667 lots → 0.16 lots.
Notice that the answer is the same as for gold. That is the point of the method: different instruments and volatility levels, but the planned loss stays roughly the same.
Details that change the result
Account currency
If your account is in a currency other than the instrument's quote currency (for example an AED, EUR or GBP account trading XAUUSD), convert the value per point into your account currency before dividing. Most platforms show this in the symbol specification or in the order window.
Spread, commission and slippage
Your real loss at the stop is usually a little larger than the calculation: you pay the spread (and commission on some accounts), and in fast markets or over weekend gaps the stop can be filled at a worse price. Around major news releases, spreads on gold can widen noticeably. Some traders add a small buffer to the stop distance or reduce size around scheduled events.
Leverage is not risk
Leverage determines how much margin a position needs, not how much you lose at the stop. A position can fit comfortably within your margin and still risk far more than you intended. Size from the stop distance first, then check margin.
Timeframe consistency
Use ATR from the same timeframe your setup is based on. A daily ATR applied to a 5-minute entry will give a stop that is far too wide for the trade idea; a 5-minute ATR on a swing trade will usually be far too tight.
A quick routine before every trade
- Read the current ATR value on your trading timeframe.
- Multiply by your tested multiplier to get the stop distance; place the stop beyond any obvious level if your rules require it.
- Calculate the risk amount from your account balance and risk percentage.
- Divide by the loss per lot at the stop, convert currency if needed, and round down.
- Check margin, spread and the economic calendar before you click.
Automating the calculation
Doing this by hand is fine, but it is easy to make a mistake under time pressure. An indicator can display the ATR stop level and a suggested lot size for your risk settings directly on the chart, and an Expert Advisor can apply the same rules automatically. If you want a tool built around your exact sizing rules, our customized indicator service covers TradingView and MT4/MT5, and our EA customization service can add ATR-based risk settings to an existing Expert Advisor. Scope and price are confirmed with you before any work begins.
For context on when volatility tends to change during the day on gold, see Trading Sessions Explained: Asia, London and New York Ranges for Gold.
Risk disclaimer: This article is for educational purposes only and is not financial, investment or trading advice. The examples are hypothetical and simplified. Trading CFDs, forex and gold is speculative and carries a high risk of losing money rapidly due to leverage; stops are not guaranteed and can be filled at worse prices in fast markets or gaps. Position sizing manages risk but cannot remove it, and no method guarantees profits. Only trade with money you can afford to lose. See our Risk Disclaimer.