Free tool
Lot size calculator for forex and gold (XAU/USD)
Enter your balance, how much you’re prepared to lose on the trade and where your stop loss goes. You get the lot size to type into MT4 or MT5, with the working shown.
Fill in the boxes above to see your lot size.
It all runs on your device: nothing you type is sent or saved.
Assumes a standard account in US dollars (1 lot = 100,000 units, or 100 ounces of gold). Spread, commission and price gaps can make a real loss bigger than shown, and the calculator doesn’t check margin. On a cent or micro account, ask your broker what a lot means there.
How the lot size is worked out
Start from the money, not the lot. Decide how much you accept losing if the trade goes wrong, put your stop loss where the trade idea is proved wrong, and the lot size follows from those two.
Lot size = amount you risk ÷ (stop loss in pips × value of 1 pip on 1 lot)
On pairs priced in dollars, like EUR/USD or GBP/USD, one pip on a full lot is worth $10. Risking $20 with a 20-pip stop gives $20 ÷ (20 × $10) = 0.10 lots. The answer is rounded down to the nearest 0.01, the smallest step brokers take, and never up, so rounding doesn’t add to the risk you chose.
Lots, units and pip values
A lot is a set amount of the currency you buy or sell. On a pair priced in dollars:
| Size | Lots | Units | 1 pip is worth |
|---|---|---|---|
| Standard | 1.00 | 100,000 | $10 |
| Mini | 0.10 | 10,000 | $1 |
| Micro | 0.01 | 1,000 | $0.10 |
Gold (XAU/USD)
On most brokers 1 lot of gold is 100 ounces, so every 1.00 move in the gold price is worth $100 on 1 lot, $10 on 0.10 lots and $1 on 0.01 lots. A few brokers and account types use 10 ounces or 1 ounce; check yours and set it under Broker settings in the calculator.
Brokers and teachers don’t agree on what a “pip” is on gold. Some count 0.01, some 0.10, some 1.00, so a 5.00 move gets called 500, 50 or 5 pips. That’s why the calculator asks for the stop as a price distance, or your entry and stop prices: 2650.00 to 2645.00 is 5.00 whatever anyone calls it.
Example: a $500 account risking 1% ($5), with the stop 5.00 away. $5 ÷ (5.00 × $100) = 0.01 lots, the smallest gold trade there is. With a wider stop the right size falls below 0.01, and the calculator tells you so instead of rounding up.
Pairs not priced in dollars
When the dollar is the first currency (USD/JPY, USD/CAD, USD/CHF), a pip on 1 lot isn’t exactly $10: it depends on the price. At USD/JPY 150 it’s about $6.67. The calculator asks for the price, or takes it from your entry.
For cross pairs like EUR/JPY or EUR/GBP it needs the price that turns the second currency into dollars: USD/JPY for the yen pairs, GBP/USD for EUR/GBP, AUD/USD for EUR/AUD and USD/CAD for GBP/CAD. Read it off your chart. Typing the cross pair’s own price instead gives the wrong answer.
On yen pairs a pip is the second decimal (150.25 to 150.45 is 20 pips). On the others it’s the fourth (1.0850 to 1.0870 is 20 pips). The extra last digit many brokers show is a pipette, a tenth of a pip.
How much to risk on one trade
That’s your call, and it decides how long an account lasts. Many traders keep it to 1–2% of the balance per trade, so that a run of losing trades, which every trader has, takes a small bite rather than the whole account. The table under your result shows what a run of losses does.
Leverage doesn’t change this. It decides how big a position your broker lets you open, not how much you lose at your stop. That comes from the lot size and the stop, which is what this calculator works out.
Size every trade before you enter, set the stop loss with the order, and leave it there.
Common questions
How do I calculate lot size in forex?
Decide the amount you’ll risk (1% of a $500 account is $5), measure your stop loss in pips, then divide: lot size = risk ÷ (stop in pips × value of 1 pip on 1 lot). On EUR/USD a pip on 1 lot is $10, so $5 ÷ (25 pips × $10) = 0.02 lots. Round down to the nearest 0.01.
How much is 1 pip on gold (XAU/USD)?
It depends on what your broker calls a pip, which is why this calculator works in price instead. With the usual 100-ounce lot, a 0.01 move is worth $1 on 1 lot, a 0.10 move $10 and a 1.00 move $100. On 0.01 lots, divide by 100: a 1.00 move is $1.
How much is 0.01 lot worth on EUR/USD and on gold?
On EUR/USD, 0.01 lots (1,000 euros) moves about $0.10 per pip, so a 20-pip stop costs about $2. On gold with a 100-ounce lot, 0.01 lots is 1 ounce: each 1.00 move in price is $1, so a 5.00 stop costs about $5.
What lot size should a beginner use with a small account, like $100?
There’s no single right number: it comes from your risk and your stop. At 1% of $100 you risk $1, which on EUR/USD with a 10-pip stop is 0.01 lots. With a wider stop, or on gold, even 0.01 lots can be more than 1% of a $100 account. The calculator shows you when, and the choice is then to skip the trade or accept the bigger risk.
Does a stop loss, or this calculator, guarantee I won’t lose more than that?
No. The calculator works out the loss at your stop price. In fast markets, at the weekly open or around big news, price can jump past a stop and fill worse (slippage), and spread and commission add to the cost. Treat the result as your planned risk, not a promise.
Why does my broker show a different contract size or pip value?
Brokers set their own contract specifications, especially for gold (100, 10 or 1 ounce per lot) and on cent or micro accounts. Prices also move, which changes the pip value on pairs not priced in dollars. In MT4 or MT5, open the symbol’s Specification to see the contract size, and for gold set it under Broker settings here.
Does leverage change how much I risk on a trade?
No. Leverage decides how much margin your broker holds, and so how big a position you can open. Your loss at the stop depends only on the lot size and the stop distance. High leverage makes it easy to open a lot that’s far too big, which is why sizing from your risk matters.
Can I use this calculator for synthetic indices (Volatility 75, Boom & Crash) or US30?
Not reliably. Synthetic and stock indices don’t use forex lots: the value of a 1.00 move per lot is set by each broker and differs between symbols. Check the contract specification in your platform. This calculator covers forex pairs and gold.
Learn it properly, free
Our free beginner courses take you from what a pip is to placing your first trade, with a short quick check after each lesson.
Start the free coursesEducational tool. The numbers are estimates: your broker’s prices, spreads and contract sizes decide the real ones. Trading carries risk, and you can lose money. New to forex in Ghana? Read the beginner’s guide.