Our free Forex lot size calculator helps you find the optimal position size for every trade. Enter your account balance, risk percentage and stop loss in pips — get the recommended lot size in seconds. No sign-up required.
What is Lot Size in Forex?
A lot is the standard unit of volume in Forex. One standard lot equals 100,000 units of the base currency. Brokers also offer mini lots (0.1 = 10,000 units) and micro lots (0.01 = 1,000 units), so you can trade with smaller capital. Choosing the right lot size is essential for risk management: too large and one loss can hurt your account; too small and you may not benefit from good moves.
How to Use the Lot Calculator
Enter your account balance in your account currency (e.g. USD). Set the risk percentage per trade — most professionals risk 1–2% per trade. Select the currency pair you are trading and the stop loss distance in pips. Click calculate to get the recommended lot size, risk amount in money, and the equivalent in mini and micro lots. Use this result when opening your trade in MetaTrader or your broker platform.
Lot Size Formula
The formula used is: Lot size = Risk amount ÷ (Stop loss pips × Pip value per standard lot). The risk amount is your balance × risk %. Pip value depends on the pair and contract size (e.g. 100,000 for standard lot on Forex). Our calculator does this math for you so you can focus on your strategy.
Lot Size = Risk Amount / (Stop Loss Pips × Pip Value)
Why Position Sizing Matters
Fixed position sizing (e.g. always 1 lot) ignores your account size and stop loss. If your account grows or shrinks, or your stop loss changes, the same lot size can mean very different risk. Using a lot calculator keeps your risk per trade consistent and helps protect your capital over the long term.