How to Calculate Lot Size: Forex and Gold

To calculate lot size, divide the amount you are willing to risk by the cost of your stop per lot: lots = (account × risk %) ÷ (stop distance in pips × pip value per lot). With $5,000, 1% risk and a 25-pip stop on EUR/USD, that is $50 ÷ $250 = 0.2 lots.

That one formula is what every lot size calculator does, and it works for any market once you know the pip value per lot. The rest of this guide explains lot sizes, pip values, worked forex and gold examples, and the broker details you need to check before relying on any number.

Lot size calculator formula: how it works

The formula, as set out in CMC Markets' guide to lot sizes, is:

Lot size = (Account balance × Risk %) ÷ (Stop-loss distance in pips × Pip value per lot)

Break it into three steps:

1. Risk amount: account balance × risk percentage. This is the most you are prepared to lose if the stop is hit.
2. Cost of the stop for one lot: stop distance in pips × pip value per standard lot.
3. Lots: risk amount ÷ cost of the stop for one lot.

The answer is in standard lots. Most platforms let you trade in steps of 0.01 lots, so you usually round down to the nearest 0.01 to stay at or under your risk amount.

Note that this calculation ignores spread, commission and slippage. A stop can be filled worse than its price in fast markets, so the actual loss can be larger than the figure you planned.

What are standard, mini and micro lots?

A lot is a fixed amount of the thing you are trading. In forex, a standard lot is 100,000 units of the base currency. For gold, a standard lot is commonly 100 troy ounces, matching the COMEX gold futures contract unit, but brokers set their own CFD sizes.

Lot type	Lots	Forex units	EUR/USD pip value	Gold ounces (common)	Gold: value of a $1 move
Standard	1.00	100,000	$10	100 oz	$100
Mini	0.10	10,000	$1	10 oz	$10
Micro	0.01	1,000	$0.10	1 oz	$1

The forex columns follow the CMC Markets figures for EUR/USD. The gold columns assume a 100 oz standard lot; check your broker's specification, because some use a different contract size.

What is the pip value for EUR/USD?

For EUR/USD, one pip is 0.0001. One standard lot is 100,000 euros, priced in US dollars, so one pip is worth:

100,000 × 0.0001 = $10 per pip per standard lot.

This $10 figure holds for any pair where the US dollar is the second (quote) currency, such as EUR/USD or GBP/USD, when your account is in US dollars. A mini lot is $1 per pip and a micro lot $0.10.

How do you calculate lot size in forex? A worked example

Example 1: $5,000 account, 1% risk, 25-pip stop on EUR/USD

1. Risk amount: $5,000 × 1% = $50.
2. Cost of the stop per standard lot: 25 pips × $10 = $250.
3. Lots: $50 ÷ $250 = 0.2 lots.

Check: 0.2 lots × $10 = $2 per pip. 25 pips × $2 = $50. That matches the risk amount.

0.2 lots is 20,000 units, the same as 2 mini lots or 20 micro lots.

Example 2: same account and risk, 40-pip stop

1. Risk amount: $50.
2. Cost of the stop per standard lot: 40 × $10 = $400.
3. Lots: $50 ÷ $400 = 0.125 lots.

Most brokers only accept steps of 0.01, so round down to 0.12 lots. Check: 0.12 × $10 = $1.20 per pip. 40 × $1.20 = $48, just under the $50 limit. Rounding up to 0.13 would put $52 at risk.

The pattern is simple: a wider stop means a smaller forex lot size for the same risk.

How do you calculate gold lot size?

Gold (XAUUSD) needs two extra checks, because brokers differ on both.

1. Contract size. With the common 100 oz per standard lot, every $1 move in the gold price is worth 100 × $1 = $100 per lot. Brokers can and do differ; for instance, RoboMarkets' XAUUSD specification lists 100 oz per lot with a minimum of 0.01 lots.

2. What a "pip" means. There is no single convention for gold pips. That same RoboMarkets page lists a pip size of 0.01, while this site's bots treat 1 pip of gold as $0.10. Under the $0.10 convention:

• 1 pip = $0.10 move = 100 oz × $0.10 = $10 per standard lot.
• 100 pips = $10 move = $1,000 per standard lot.
• 200 pips = $20 move = $2,000 per standard lot.

The simplest way to avoid confusion is to work in dollars of price movement instead of pips. The free XAUUSD lot size calculator does exactly that, and shows the pip value under both conventions.

Example 3: $5,000 account, 1% risk, gold stop $6 away

1. Risk amount: $5,000 × 1% = $50.
2. Cost of the stop per standard lot: $6 move × 100 oz = $600. (In pips at $0.10 each: 60 pips × $10 = $600, the same answer.)
3. Lots: $50 ÷ $600 = 0.0833 lots.

Round down to 0.08 lots, which is 8 oz. Check: 8 oz × $6 = $48, just under $50.

With targets at 1× and 2× the risk, TP1 is a $6 move and TP2 a $12 move, worth 8 oz × $6 = $48 and 8 × $12 = $96 at 0.08 lots. These are simply the sizes of those price moves at this position size, not expected results.

Example 4: a wide gold stop

Same $50 risk, but the stop is $25 away. Cost per standard lot: $25 × 100 = $2,500. Lots: $50 ÷ $2,500 = 0.02 lots (2 oz). Check: 2 × $25 = $50.

What if my account is not in US dollars?

The pip value per lot depends on the quote currency of the pair, so convert it into your account currency before using the formula.

• Pair quoted in another currency. On EUR/GBP, a standard lot pip is 100,000 × 0.0001 = £10. With a US dollar account and GBP/USD at 1.2500 (an illustrative rate), that is £10 × 1.25 = $12.50 per pip.
• Yen pairs. On USD/JPY, a pip is 0.01, so a standard lot pip is 100,000 × 0.01 = ¥1,000. At USD/JPY 150.00 (illustrative), that is ¥1,000 ÷ 150 = about $6.67 per pip.
• Non-USD account on a USD-quoted pair. On EUR/USD with a euro account, $10 per pip is converted at the current EUR/USD rate.

A broker's built-in lot size calculator does these conversions using live rates, which is easier than doing it by hand.

What should I check with my broker?

Before trusting any lot size number, open your broker's contract specification for the symbol (in MetaTrader, the symbol's specification window) and confirm:

• Contract size: units or ounces per standard lot.
• Minimum lot and lot step: often 0.01, but not always.
• Tick or pip size: especially for gold, where conventions vary.
• Account currency: so you know whether pip values need converting.

How our bots use this

The Scalper, Basic Day and the other bots run the same fixed, backtested smart money concepts rules as code. Each one marks order block reaction areas, and says BUY or SELL when price returns to a top-tier block with the trend in the right session (London 07:00–10:00 UTC or New York 12:00–16:00 UTC for Scalper and Basic Day; see session times for gold). The full rules are on the methodology page.

What the bots give you for sizing:

• Entry zone: the whole order block candle.
• Stop: 0.1× ATR beyond the sweep wick for top-tier blocks, otherwise 0.5× ATR beyond the far edge of the zone.
• Targets: TP1 = 1× and TP2 = 2× the risk, measured from the zone edge, on every market including gold.

The bots do not choose your lot size. Plug the stop distance into the formula above, or into the gold lot size calculator, using your own account and risk.

FAQ

What lot size should I use for a $1,000 account?

It depends on your risk percentage and stop distance, not the account alone. At 1% risk ($10) and a 20-pip stop on EUR/USD, the cost per standard lot is 20 × $10 = $200, so $10 ÷ $200 = 0.05 lots.

How much is 0.01 lot of gold worth per $1 move?

With a 100 oz standard lot, 0.01 lots is 1 oz, so a $1 move is worth $1. If your broker uses a different contract size, the figure changes.

Is a pip on gold $0.01 or $0.10?

It depends on the broker or tool. Some platforms list 0.01, and this site's bots use $0.10. Converting the stop to a dollar price move avoids the confusion.

Does a lot size calculator include spread and commission?

Usually not. Most calculators size the position from the stop distance only, so trading costs and slippage can make the actual loss larger.

Free tools for this: see how a losing streak at your risk per trade would hit the account with the drawdown calculator, and check your targets with the risk reward calculator. Trading a prop firm challenge? The FTMO consistency rule caps how much of your total profit one day can make, which is one more reason to size every trade from a fixed risk.

This is educational content, not financial advice.