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Lot size and risk calculator.
Decide how much you are willing to lose, tell it where your stop is, and get the exact lots. Below the result you get the full working, step by step, so you understand it rather than trust it.
Calculator
Position size
—lots
The working
Step by step, with your numbers.
Change any input above and watch each line update. This is exactly what the calculator does — nothing hidden.
What if
The same trade at different risk levels.
Risk per trade looks like a small decision. These two tables show why it is the biggest one you make.
| Risk | Money at risk | Lots | After 10 straight losses |
|---|
| Streak | Balance left | Drawdown | Needed |
|---|
Understand it
How position sizing really works.
Most traders who blow an account do not fail on the entry — they fail on the size. They open “0.50 because” and find out afterwards how much money that was. Position sizing reverses the order: first decide how much you can lose, then the size falls out.
The formula
lots = (balance × risk %) ÷ (stop × pip value per lot)
It has three parts and each one is worth understanding on its own.
1. Money at risk
This is the only number you choose freely. 1% of $10,000 is $100. That is what you lose if price reaches the stop, and it should be an amount you could lose ten times in a row without it changing how you trade.
2. Pip value
A pip is the fourth decimal of the price (0.0001) on almost every pair, and the second (0.01) on yen pairs. A standard lot is 100,000 units of the base currency, so one pip is worth 0.0001 × 100,000 = 10 units of the quote currency.
- EUR/USD, GBP/USD, AUD/USD… are quoted in dollars: the pip is worth $10 per lot.
- USD/JPY, EUR/JPY… are quoted in yen: the pip is worth ¥1,000 per lot, which must be converted to your currency.
- EUR/GBP is quoted in pounds: £10 per lot.
If the quote currency is not your account currency, it is converted at the current rate. That is why the pip value of USD/JPY changes daily for a dollar account, and EUR/USD changes for a euro account.
3. The stop
The chart decides the stop, not your wallet. If the analysis calls for 80 pips, it is 80; what you adjust is the lot size. The classic mistake is the reverse: fixing the lots and tightening the stop until the risk “fits”, which guarantees you get stopped out by noise.
Gold and indices: forget pips
On XAUUSD one lot is usually 100 ounces. If gold moves $1, one lot makes or loses $100. Some brokers call 0.01 a pip and others 0.10, so two traders can both say “20 pips” and mean risks ten times apart. The safe way is to measure the stop in price: entry 2,650, stop 2,645, distance 5. On indices the contract size varies even more between brokers (1, 10 or 100 per point): open the symbol specification in MT5 (right click → Specification) and copy the “Contract size”.
What the calculator cannot know
- Slippage and gaps: around news or opens the stop can fill worse than your price. Real risk can exceed the calculated one. Check the economic calendar before sizing.
- Spread and commission: they add to the loss. On tight stops (under 10 pips) they can be an extra 10–20%.
- Correlation: three 1% trades on EUR/USD, GBP/USD and AUD/USD are not three 1% risks — they behave a lot like one 3% risk.
FAQ
Frequently asked questions.
How do you calculate lot size in forex?
Divide the money you accept to lose by what each lot loses if the stop is hit: lots = (balance × risk %) ÷ (stop in pips × pip value per lot). With $10,000, 1% risk and a 50-pip stop on EUR/USD: 100 ÷ (50 × 10) = 0.20 lots.
How much is one pip worth?
On a standard lot (100,000 units) of any pair ending in USD, one pip is worth $10. On JPY pairs the pip is 0.01 and is worth ¥1,000 per lot. If your account is in another currency that value is converted at the current exchange rate; the calculator does it for you and shows the working.
What percentage should I risk per trade?
The most common reference is 0.5% to 1% of balance. It is arithmetic rather than a law: at 1% you survive 10 straight losses at −9.6%; at 5% those same 10 losses leave you at −40% and you need +67% to get back to where you started.
Why does the calculator round lots down?
Because the broker only accepts multiples of its minimum step (usually 0.01). If the maths says 0.237 lots, opening 0.24 exceeds your risk; 0.23 respects it. Always rounding down guarantees you never risk more than you decided.
How do I size a gold (XAUUSD) trade?
At most brokers 1 lot of XAUUSD is 100 ounces, so every $1 move in price is $100 per lot. Because brokers disagree on what a gold “pip” is, here you enter the stop as a price distance: a $5 stop on 1 lot is $500 of risk.
Does it work for prop firm accounts?
Yes. Under the result you will see how much of a 5% daily loss limit the trade uses. To manage the whole account — daily limit, max loss, target and odds of passing — use the prop firm account manager.
Is my data sent anywhere?
No. All the maths runs in your browser. The only outside connection is downloading the reference exchange rates, which carries none of your data.
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See the product →Educational tool. Results are indicative and are not financial or investment advice. Leveraged trading can lose you all of your capital. Always check the symbol specification at your broker and the current rules of your prop firm.