Margin is calculated two ways: Used Margin and Free Margin. Used margin is the amount of money used to hold open positions. Free margin is the amount of funds available to place additional positions. The Margin level is calculated by dividing the current equity in an account by the current amount of margin in use (used margin). After dividing the equity by the margin move the decimal two places to the right. A trader whose equity is at $10,000 and who is using a $5,000 of margin would divide 10,000 by 5,000 which of course equals 2. Then move the decimal two places to the right. Thus, the current margin level or percentage is 200%. At a 100% margin level a trader is essentially using his entire available margin. (See formula below).

Margin Level Calculation % = Equity*/ Used Margin
* (Account balance considering ALL open positions)