How to Calculate Margin in Forex
What is Forex Margin?
Margin is not a fee or cost; it is a security deposit that your broker holds to cover potential losses. In forex, you can control a large position with a relatively small deposit thanks to leverage. For example, with 1:30 leverage (the maximum for Israel retail traders under ISA rules), you need only $3,333.33 to control $100,000 worth of currency.
The Margin Formula
The basic formula is: Margin = (Trade Size × Market Price) ÷ Leverage. Trade size is measured in lots (standard lot = 100,000 units, mini lot = 10,000, micro lot = 1,000). Market price is the current exchange rate of the base currency against USD. Leverage is the multiplier provided by your broker.
Example for Israel Traders
Suppose you want to buy 1 mini lot (10,000 units) of EUR/USD at a price of 1.10, and your broker offers 1:30 leverage. Margin = (10,000 × 1.10) ÷ 30 = $366.67. If you deposit via Bank Transfer or Skrill, you need at least $366.67 in your account. With USDT, convert the amount first.
Margin vs Free Margin
Used margin is the amount locked for open positions. Free margin is the equity minus used margin — it determines how many more trades you can open. For Israel traders, always keep free margin above 100% of used margin to avoid margin calls.
How Leverage Affects Margin
Higher leverage means lower margin requirement but higher risk. The ISA limits leverage to 1:30 for major pairs and 1:20 for minors to protect local traders. Always choose leverage that matches your risk tolerance and account size.