Used margin is the capital your broker reserves when you open a position. Calculated as your lot size divided by leverage ratio, it acts as your security deposit for that trade until you close it.
How Used Margin Is Calculated
Used margin depends on position size and leverage:
Used Margin = Lot Size ÷ Leverage
For example, trading one standard lot (100,000 units) of EUR/USD with 50:1 leverage reserves $2,000 in margin ($100,000 ÷ 50).
Why Used Margin Matters for Your Account
Used margin directly cuts into your available trading capital. It determines your free margin—the money left to open new trades. High used margin relative to your equity leaves little cushion for losses.
Leverage amplifies this problem. Higher leverage locks up more margin per trade, tightening your safety margin. If used margin consumes too much of your equity, even a small adverse price move can exhaust your free margin and trigger a margin call, forcing automatic position closure.
