Calculate the exact position size for your trade based on your account balance, risk tolerance, and stop loss — instantly and free.
Pip values for pairs not quoted directly in USD (e.g. USD/JPY, EUR/GBP, cross pairs) are approximate and move with live exchange rates. For exact figures, check your broker's contract specifications or use the "Custom" pair option and enter the exact pip value yourself.
In forex trading, lot size refers to the number of currency units you're buying or selling in a trade. It's the trading equivalent of "how many shares" in the stock market. Choosing the correct lot size is one of the most important risk management decisions a trader makes, because it directly determines how much money is at stake if a trade goes wrong.
Unlike stop loss or take profit, which many new traders think about carefully, position sizing is often overlooked — yet it's usually the single biggest factor separating traders who survive drawdowns from those who blow their accounts on one bad trade.
This calculator uses the standard position-sizing formula used by professional traders and risk managers:
Where Risk Amount is either your chosen percentage of account balance, or a fixed dollar figure you enter directly. This formula makes sure that no matter how tight or wide your stop loss is, the dollar amount you risk stays consistent with your risk plan.
Forex position sizes come in a few standard increments:
| Lot Type | Units | Typical Use |
|---|---|---|
| Standard Lot | 100,000 units | Larger accounts, experienced traders |
| Mini Lot | 10,000 units | Mid-sized accounts, common for swing trading |
| Micro Lot | 1,000 units | Small accounts and beginners learning risk control |
| Nano Lot | 100 units | Offered by some brokers for ultra-fine sizing |
Two traders can take the exact same setup, on the exact same pair, with the exact same stop loss — and end up with completely different outcomes purely because of lot size. Trading too large a position relative to account size is one of the most common reasons new traders lose money quickly, even when their trade analysis is correct.
A widely used rule among consistently profitable traders is to risk no more than 1–2% of account equity per trade. This keeps any single loss small enough that a losing streak doesn't meaningfully damage the account, while still allowing gains to compound over time.
For small accounts, micro lots (0.01) are usually the only sensible option. On a $100 account risking 1% ($1) with a 20-pip stop loss on a USD-quoted pair, that works out to roughly a 0.01 lot position — this calculator will show the exact figure for your numbers.
For most pairs quoted directly against the US dollar (like EUR/USD or GBP/USD), one pip on a standard lot (100,000 units) is worth approximately $10. For pairs where USD is the base currency, or for cross pairs, the pip value varies with the live exchange rate.
Most professional risk management guidelines recommend risking 1–2% of account balance per trade. Risking more than this significantly increases the chance of large drawdowns during a losing streak.
Yes. Larger lot sizes require more margin to open and maintain the position. This calculator focuses on risk-based position sizing; always check your broker's margin requirements separately before placing a trade.