How to Calculate Margin in Forex
Understanding the Margin Formula
The basic margin formula is: Margin = (Lot Size × Contract Size) / Leverage. For forex, the standard contract size is 100,000 units for 1 standard lot, 10,000 for a mini lot, and 1,000 for a micro lot. The base currency is always the first currency in the pair.
Example for Greece Traders (EUR/USD)
Suppose you trade EUR/USD with a USD-denominated account. You want to open 1 standard lot (100,000 EUR) with 1:30 leverage. Margin = 100,000 / 30 = 3,333.33 USD. If your account balance is 10,000 USD, your used margin is 3,333.33 USD, leaving 6,666.67 USD as free margin. This free margin determines how many pips you can lose before a margin call.
Example for GBP/USD
For GBP/USD, the base currency is GBP. With 1 mini lot (10,000 GBP) and 1:30 leverage: Margin = 10,000 / 30 = 333.33 GBP. If GBP/USD is at 1.2500, that equals 416.66 USD. Always convert the margin to your account currency (USD) at the current exchange rate.
Margin for Cross Pairs and Exotics
For pairs like EUR/JPY or GBP/AUD, the margin is calculated based on the base currency (EUR or GBP). If your account is in USD, you convert the base currency to USD. For example, 1 lot EUR/JPY at 1:30 requires 100,000 / 30 = 3,333.33 EUR, converted to USD at the EUR/USD rate.
How Leverage Affects Margin
Higher leverage reduces margin but increases risk. Under HCMC rules, retail traders in Greece are capped at 1:30 for major pairs, 1:20 for non-major pairs, and 1:10 for commodities. Professional traders can access up to 1:500, but they must apply and meet criteria like a €500,000 portfolio. Always use a margin calculator provided by your broker to avoid errors.