Initial Margin is the amount of collateral required to open a position for Leverage trading.
To calculate the initial margin, the system will take the Contract Quantity / ( Order Price x Leverage). The initial margin rate depends on the leverage used. Assuming you are using 100x leverage for 100 BTC contract value, you would only need to invest 1 BTC as your initial margin (1/100).
To check the initial margin rate for your position, and the maximum leverage you can use, you may refer to the Risk limit table.
A trader buys 12,000 BTCUSD contracts at 8,000 USD with 50x leverage.
= 0.03 BTC