Tool
Lot size calculator
Lot size is the risk you can afford divided by what your stop costs on one lot. Multiply your balance by your risk percentage, then divide by the stop in pips times the pip value per lot. On a $5,000 account risking 1% with a 25-pip EUR/USD stop, that's $50 ÷ $250 = 0.20 lots.
Result
0.20lots
- Units
- 20,000 units
- Risk budget
- $50.00
- Money at risk
- $50.00
- Pip value / lot
- $10.00
Exact size 0.2000 lots, rounded down to the nearest 0.01 so you never risk more than planned.
Results assume a US dollar account and standard contract sizes. Your calculations stay in your browser; nothing is sent anywhere.
The formula
Lots = (Balance × Risk %) ÷ (Stop in pips × Pip value per lot)
The pip value per standard lot depends on the pair, because the profit or loss is paid in the pair's quote currency:
- EUR/USD, GBP/USD and other XXX/USD pairs: 100,000 × 0.0001 = $10 per pip.
- USD/JPY: 100,000 × 0.01 = ¥1,000 per pip, which is 1,000 ÷ the USD/JPY price in dollars.
- GBP/JPY and other JPY crosses: also ¥1,000 per pip, converted at the USD/JPY rate.
- USD/CAD and USD/CHF: 100,000 × 0.0001 = 10 units of the quote currency, which is 10 ÷ the pair's price in dollars.
- XAU/USD (gold): 100 oz × $0.01 = $1 per pip.
Units are the lots times the contract size: 0.20 lots of EUR/USD is 20,000 euros, and 0.10 lots of gold is 10 ounces.
For any other pair or a euro or pound account, the pip calculator works out the pip value per lot.
Worked examples
EUR/USD: $5,000 account, 1% risk, 25-pip stop
The risk budget is $5,000 × 1% = $50. A 25-pip stop on one standard lot costs 25 × $10 = $250. $50 ÷ $250 = 0.20 lots, or 20,000 units, risking exactly $50.
Gold: $5,000 account, 1% risk, $5.00 stop
A $5.00 move is 500 pips at $0.01 each. One lot loses 500 × $1 = $500 over that move, so $50 ÷ $500 = 0.10 lots, or 10 ounces. Check: 10 oz × $5.00 = $50.
USD/JPY at 150.00: $5,000 account, 1% risk, 30-pip stop
One pip on a standard lot is ¥1,000, or 1,000 ÷ 150 = $6.67. Thirty pips cost $200 per lot, so $50 ÷ $200 = 0.25 lots. Check: 25,000 × 0.30 yen = ¥7,500, which is $50 at 150.00.
Why size from the stop, not the other way round
Put the stop where the trade idea is proven wrong, beyond the swing or level that matters, and then let the size follow. Traders who pick a lot size first and squeeze the stop to fit tend to get stopped out by normal noise. A wider stop simply means a smaller position for the same money at risk.
Many traders cap risk at 1–2% of the account per trade so a losing run doesn't do lasting damage. That is a convention, not a rule; choose a figure you could lose several times in a row without changing how you trade.
Common mistakes
- Using $10 a pip for every pair. It only holds when the US dollar is the quote currency and your account is in dollars.
- Mixing up gold pip conventions. Confirm whether your platform calls $0.01 or $0.10 a pip before you enter a stop.
- Forgetting spread and commission. They add to the real cost of a trade, so leave a little room under your risk budget.
- Sizing from equity you don't have. Use your current balance, not last month's high.
Lot sizing in StraviFX
When StraviFX reads a chart, it plans the entry, stop and two targets, then sizes the position from your account equity and risk percentage, using the same stop-first method. See what the app does or learn the basics of trading first.
FAQ
What is a standard, mini and micro lot?
A standard lot is 100,000 units of the base currency, a mini lot is 10,000 (0.10 lots) and a micro lot is 1,000 (0.01 lots). For gold, one standard lot is usually 100 troy ounces, so 0.01 lots is 1 ounce. Check your broker's contract specification, because a few use different sizes.
What lot size should I use on a $100 account?
Risking 1% of $100 is $1. With a 20-pip stop on EUR/USD, one standard lot risks $200, so the size would be 0.005 lots, below the 0.01 minimum many brokers allow. The honest answer is that a small account limits how tight your risk can be, so either accept fewer trades that fit or skip the ones that don't.
Why does the calculator round down?
Brokers trade in steps, usually 0.01 lots. Rounding up would risk more than you planned, so the calculator always rounds down and shows the money actually at risk after rounding.
How are pips counted on gold?
This calculator counts one gold pip as a $0.01 move in the XAU/USD price, which is worth $1 on one 100-ounce lot. Some brokers and platforms call $0.10 a pip instead. If yours does, multiply your stop by ten before entering it, so a $5.00 move is 500 pips here.
Why do USD/JPY and USD/CAD need a price?
When the US dollar isn't the quote currency, a pip is worth a fixed amount of yen or Canadian dollars, not dollars. Turning that into US dollars needs the current exchange rate, so the calculator asks for it.
Get StraviFX
Point your camera at any chart and StraviFX reads the structure, plans the entry, stop and targets, and sizes your risk. Free to download on Android, with optional subscriptions.
