How does OKX calculate required margin for futures?

OKX futures margin depends on leverage, position size, and margin mode—isolated locks fixed margin, while cross uses total account balance as collateral.

Aug 10, 2025 at 04:08 pm

Understanding Margin in OKX Futures Trading

In futures trading on OKX, the required margin refers to the amount of funds a trader must set aside to open and maintain a leveraged position. This margin acts as collateral to cover potential losses. The calculation of required margin depends on several key factors including leverage, contract size, entry price, and margin mode. Traders can choose between isolated margin and cross margin modes, each influencing how margin is allocated and calculated.

When using isolated margin, the margin is fixed for a specific position. This means the system calculates the required margin based on the position size and the leverage selected. For example, opening a $10,000 position with 10x leverage requires a $1,000 margin. This margin is isolated and will not be affected by other positions in the account.

In contrast, cross margin uses the entire available balance in the futures wallet as potential collateral. The required margin in this mode is dynamically calculated based on the current equity and unrealized P&L of all open positions. While this provides more flexibility, it also increases the risk of liquidation if the overall account value drops.

Components Influencing Required Margin Calculation

The required margin is not a static value and is influenced by multiple parameters. The most critical factors include:

• Position size in USD or contracts
• Entry price of the futures contract
• Leverage level selected
• Margin mode (isolated or cross)
• Funding rate adjustments (in perpetual contracts)

For linear futures contracts, which are settled in stablecoins like USDT, the required margin is calculated as:

Required Margin = (Position Size in USD) / (Selected Leverage)

For inverse futures contracts, which are settled in the base cryptocurrency (e.g., BTC), the formula adjusts to account for price volatility and denomination in the underlying asset:

Required Margin = (Contract Size in USD) / (Entry Price × Leverage)

These formulas are applied in real time by the OKX risk engine, ensuring that margin requirements reflect current market conditions and user-defined settings.

Step-by-Step Margin Calculation Example

To illustrate how OKX calculates required margin, consider the following scenario:

• Trading pair: BTC/USDT
• Contract type: USDT-margined perpetual futures
• Position size: 1 BTC
• Entry price: $60,000
• Leverage: 20x
• Margin mode: Isolated

First, calculate the total position value:

Position Value = 1 BTC × $60,000 = $60,000

Next, apply the leverage to determine the required margin:

Required Margin = $60,000 / 20 = $3,000

This $3,000 is locked as initial margin for the position. If the trader had selected 10x leverage, the required margin would increase to $6,000, reducing the risk of liquidation but requiring more capital upfront.

In cross margin mode, the same calculation applies initially, but the system continuously monitors the total account balance. If other positions incur losses, the available margin for this BTC position decreases, potentially triggering a margin call or liquidation.

Impact of Maintenance Margin and Liquidation

Beyond the initial required margin, OKX also enforces a maintenance margin threshold. This is the minimum amount of margin that must be maintained to keep the position open. If the account’s margin balance falls below this level due to adverse price movements, the position faces liquidation.

The maintenance margin is a percentage of the position value and varies by instrument and leverage. For example, with 20x leverage on BTC/USDT futures, the maintenance margin rate might be 0.5% of the position value.

Using the earlier example:

Maintenance Margin = $60,000 × 0.5% = $300

This means the trader must maintain at least $300 in margin equity for the position to remain open. If the unrealized loss reduces the margin balance below this threshold, OKX’s liquidation engine will trigger.

The liquidation price is calculated in real time and depends on the entry price, leverage, and funding fees. Traders can view this price in the position panel on the OKX trading interface.

Adjusting Leverage and Its Effect on Margin

OKX allows traders to adjust leverage before or after opening a position, which directly affects the required margin. Increasing leverage reduces the required margin, increasing risk exposure. Decreasing leverage raises the required margin, enhancing safety.

To adjust leverage on OKX:

• Navigate to the futures trading interface
• Select the desired trading pair (e.g., ETH/USDT)
• Locate the leverage selector (usually displayed near the order panel)
• Click to choose a new leverage level (e.g., from 10x to 25x)
• Confirm the change

After adjustment, the required margin is recalculated instantly. For example, reducing leverage from 25x to 10x on a $50,000 position increases the required margin from $2,000 to $5,000. The additional $3,000 is deducted from available balance or triggers a margin call if insufficient funds exist.

It’s important to note that changing leverage in isolated margin mode only affects the selected position. In cross margin, adjusting leverage for one position may indirectly impact others due to shared margin resources.

Viewing and Managing Margin on OKX Platform

Traders can monitor required margin and related metrics directly within the OKX futures dashboard. Key steps include:

• Log in to the OKX website or app
• Go to Trade > Futures
• Select the contract (e.g., BTC-USDT-SWAP)
• Open the Positions tab
• View fields such as Initial Margin, Maintenance Margin, Leverage, and Liquidation Price

The interface also displays margin ratio, calculated as:

Margin Ratio = (Equity / Maintenance Margin) × 100%

When this ratio drops to 100%, liquidation occurs. Users can add additional margin manually to avoid this:

• Click “Add Margin” next to the position
• Choose the amount to transfer
• Confirm the transfer from spot wallet to futures wallet

This action increases the margin balance and lowers the liquidation risk.

Frequently Asked Questions

Does OKX charge interest on required margin?

No, OKX does not charge interest on the margin used for futures positions. However, traders may incur funding fees in perpetual contracts, which are exchanged between long and short positions every 8 hours based on the funding rate.

Can required margin change after opening a position?

Yes, in cross margin mode, the effective margin allocated to a position can fluctuate due to changes in account equity from other positions. In isolated margin, the initial margin remains fixed unless manually adjusted, but the maintenance margin requirement may vary with market volatility.

What happens if my margin falls below maintenance level?

If the margin balance drops below the maintenance threshold, OKX initiates a liquidation process. The system automatically closes the position at the prevailing market price to prevent further losses. A liquidation fee may be charged based on the contract type.

How is margin calculated for multi-position accounts in cross mode?

In cross margin, the total account balance serves as shared collateral. The required margin for each position is calculated individually, but the system evaluates the aggregate risk. Unrealized P&L from all positions affects the available margin for every open trade.