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A lot size calculator answers the key question before every trade: how big should the position be so that, if the stop loss is hit, you lose exactly the amount you planned. Enter your balance, risk as a percentage (or a fixed amount) and the stop — and get the lot size. It works for currency pairs, gold, silver, oil, indices and crypto, for accounts in USD, EUR, GBP, RUB and for cent accounts.
How to use the lot size calculator
- Account currency. Pick the currency of your trading account. For a cent account choose USC: enter the balance in cents and the result is in cent lots.
- Account balance — what is on the account now. Use the current balance, not the starting one: position size should shrink after losses and grow after profits.
- Risk per trade — as a percentage of the balance or as a fixed amount (switch “% / amount”).
- Stop loss — in pips or by price. If you think in chart levels, switch to “by price” and enter the entry and stop prices; the distance is calculated for you.
- Instrument. It sets the pip value. The contract specification is shown under the list.
On the right you instantly see the position size, the loss if the stop is hit, the pip value for that size and the profit if your take profit is 2 or 3 times the stop. “Copy link to this calculation” saves every field in the URL, so you can send the calculation to a friend or come back to it later.
Lot size formula
The calculator uses the standard money management formula:
Lot size = Amount at risk ÷ (Stop in pips × Pip value of 1 lot)
Amount at risk = Balance × Risk % ÷ 100. The result is rounded down to the 0.01 lot step, so the real loss at the stop never exceeds your risk.
Example 1. EUR/USD
Balance $1,000, risk 2%, stop 30 pips. Amount at risk = $20. One pip on 1 lot of EUR/USD is worth $10. Lot = 20 ÷ (30 × 10) = 0.0667 → 0.06 lots. If the stop is hit, you lose $18.
Example 2. Gold, XAU/USD
Balance $5,000, risk 1%, stop 150 pips (a $15 move in price). Amount at risk = $50. One gold pip (0.1) on 1 lot is worth $10. Lot = 50 ÷ (150 × 10) = 0.033 → 0.03 lots.
Example 3. USD/JPY
Balance $2,000, risk 1.5%, stop 25 pips. Amount at risk = $30. For yen pairs a pip is 0.01 and its value depends on the rate: at USD/JPY = 150 one pip on 1 lot is about $6.67. Lot = 30 ÷ (25 × 6.67) = 0.18 lots. The calculator uses a fresh exchange rate, so for crosses it is more accurate than a back-of-the-envelope estimate.
Pip value by instrument
Value of one pip for 1 standard lot (typical contracts — your broker may differ):
| Instrument | Pip | Pip value, 1 lot |
|---|---|---|
| EUR/USD, GBP/USD, AUD/USD, NZD/USD | 0.0001 | $10 |
| USD/JPY, EUR/JPY, GBP/JPY | 0.01 | ≈ $6–7 (depends on the yen rate) |
| USD/CHF, USD/CAD | 0.0001 | ≈ $7–13 (depends on the rate) |
| XAU/USD (gold, 100 oz) | 0.1 | $10 |
| XAG/USD (silver, 5,000 oz) | 0.01 | $50 |
| WTI, Brent (1,000 barrels) | 0.01 | $10 |
| US500, US30, NAS100 | 1 | $1 |
| BTC/USD, ETH/USD (1 coin) | $1 | $1 |
How much to risk per trade
The professional rule of thumb is 1–2% of the account per trade. Every strategy has losing streaks, and what matters is surviving them. Here is what is left after 10 losing trades in a row:
| Risk per trade | Drawdown after 10 losses in a row | Gain needed to break even |
|---|---|---|
| 1% | −9.6% | +10.6% |
| 2% | −18.3% | +22.4% |
| 5% | −40.1% | +67.0% |
| 10% | −65.1% | +186.8% |
That is why the calculator warns you when the risk is above 5%.
Pips vs. points in MetaTrader
In this calculator a pip is 0.0001 for most pairs and 0.01 for yen pairs. MetaTrader 4 and 5 with 5-digit quotes call a tenth of that — 0.00001 — a “point”. So if the terminal shows the stop as 300 points, enter 30 pips here. To avoid confusion, use the “by price” mode and simply type the entry and stop prices.
Lot size on a cent account
With a small balance the calculator often returns less than 0.01 lots, and a broker will not open such a trade. The fix is a cent account: the balance is counted in cents and a lot is 100 times smaller. Choose USC, enter the balance in cents (for example, $10 = 1,000 USC) and you get the size in cent lots. Brokers with cent accounts are compared in our broker rating.
The same calculator inside MT4 and MT5
Copying numbers from the browser to the terminal every time is slow. The same calculation is built into our free EA S4U.PRO Trade Panel: drag the entry, stop and take profit lines on the chart, and the panel sizes the lot by your risk and opens the trade in one click. Get it from our Telegram bot @s4u_panel_bot.
FAQ
How do I calculate lot size in forex?
Divide the amount you are willing to risk by the stop in pips multiplied by the pip value of one lot. For example, $20 ÷ (30 pips × $10) = 0.06 lots on EUR/USD. The calculator above does this for any instrument.
What percentage of my account should I risk per trade?
Usually 1–2%. At that level even 10 losses in a row leave the account in working shape (a 10–18% drawdown). Risking more than 5% per trade quickly leads to deep drawdowns.
Why does the calculator round the lot down?
Brokers accept volume in 0.01-lot steps. Rounding down guarantees the loss at the stop never exceeds your risk. The unrounded value is shown as “Exact size”.
What if the lot size is below 0.01?
Tighten the stop, increase the risk, or trade a cent account where the minimum volume is 100 times smaller. For a small balance a cent account is the safest option.
Does it work for gold, oil, indices and crypto?
Yes. For each instrument the calculator uses a typical contract size and pip value. Brokers may use different contracts for metals, indices and crypto — check the symbol specification in your terminal (right-click the symbol → Specification).
My terminal shows a 300-point stop. What do I enter?
30. With 5-digit quotes MetaTrader counts points of 0.00001, while the calculator uses classic pips of 0.0001. Or switch to “by price” and enter the entry and stop prices.
