Lot Size Calculator
Determine the correct forex lot size based on your account balance, risk percentage, and stop loss.
Pip value varies by currency pair and broker. Verify with your broker.
Assumes $10 pip value per standard lot — accurate for EUR/USD and most major forex pairs. Gold (XAU/USD), exotic pairs, and non-forex instruments use different pip values. Always verify with your broker.
How to use the lot size calculator
This free lot size calculator for forex traders removes the guesswork from position sizing. Enter your account balance, the percentage of capital you are prepared to risk on the trade, and your stop loss in pips. The calculator applies the standard lot size formula — risk amount divided by stop loss pips multiplied by pip value — to output the correct lot size instantly.
Understanding forex lot size is fundamental to consistent risk management. A standard lot represents 100,000 units of the base currency, a mini lot 10,000 units, and a micro lot 1,000 units. Each tier changes the pip value proportionally, which in turn affects how many pips you can afford to lose before hitting your risk limit.
Most professional traders risk between 0.5% and 2% of their account per trade. By fixing the risk amount first and then calculating lot size from your stop loss, you ensure that every trade is sized to your plan rather than your gut. This approach keeps drawdowns manageable and allows you to trade longer strings of losses without account-threatening damage.
Frequently asked questions
What is a lot size in forex?
A lot size is a standardised unit of measurement for a forex trade. A standard lot equals 100,000 units of the base currency. Mini and micro lots are 10,000 and 1,000 units respectively, giving traders with smaller accounts a proportional way to participate in the market.
How do I calculate the correct lot size?
Divide your risk amount (account balance × risk percentage) by the stop loss in pips multiplied by the pip value per lot. For EUR/USD standard lots the pip value is approximately $10, so: lot size = risk amount ÷ (stop loss pips × $10). This calculator performs that maths automatically.
What is a standard lot vs mini lot vs micro lot?
A standard lot is 100,000 units of the base currency, a mini lot is 10,000 units, and a micro lot is 1,000 units. Smaller lot types let traders with limited capital maintain proportionate risk without over-exposing their account on each trade.
Why is lot size important for risk management?
Lot size directly controls how much money you gain or lose per pip. Trading too large a lot size relative to your account can wipe out a significant portion of capital on a single trade, even with a tight stop loss. Correct lot sizing is the most practical tool for preserving your account through losing runs.
Does lot size affect my pip value?
Yes. Pip value scales proportionally with lot size. A standard lot on EUR/USD has a pip value of roughly $10, a mini lot roughly $1, and a micro lot roughly $0.10. Knowing your pip value before entering is essential for accurate risk calculation across different currency pairs and lot sizes.