Used Margin increases with each additional trade. In MT4, margin requirements are determined by the base currency of a pair (margin currency for CFDs vary according to the underlying instrument: see “Margin Currency” in MT4 product Specifications). Used margin is automatically converted to your account currency. In MT4, Used Margin is referred to simply as Margin. Example: AUD MT4 Account; 1:100 leverage; and, 3 buy trades for AUDUSD, XAUUSD and GBPAUD:

1. Buy 1 Lot AUDUSD 1 Lot x 100,000 x 1% = 1,000 Required Margin. Because AUD is the base of the currency pair, no conversion is required since your MT4 account currency is AUD.
2. Buy 1 Lot XAUUSD, with current market price of XAUUSD at 1,368.61 1 Lot x 100 x 1,368.61 x 1% = 1,368.61 Required Margin.
3. We need to convert XAU into AUD (XAUUSD margin is priced in USD). This can be done by dividing 1,368.61 by the AUDUSD rate, which is 0.75029 at the time of opening the trade: 1,368.61 ÷ 0.75029 = 1,824.11 Required Margin in AUD
4. Buy 1 Lot GBPAUD 1 Lot x 100,000 x 1% = 1,000 Required Margin.
5. AUD is the term currency of the pair, GBPAUD. We convert to AUD simply by multiplying by the GBPAUD rate, which is 1.72510. 1,000 x 1.72510 = 1,725.10 Required Margin in AUD.
6. By combining all the required margins you will have a Used Margin of 4,549.21.
7. To get the Margin Level in MT4: assuming your equity hasn’t changed from the original balance, divide 10,000 by 4,549.21 and multiply by 100 to get: 10,000 ÷ 4,549.21 x 100 = 219.81%.