Portfolio Margin Calculator

Portfolio margin is a risk-based margining method that calculates requirements based on the net risk of a portfolio across all positions, rather than treating each position independently. It typically requires less margin than traditional Reg T margin for hedged or diversified portfolios, and is available to accounts with $100,000+ at most US brokers.

Regulation T, set by the Federal Reserve, requires traders to deposit at least 50% of the purchase price of marginable securities when opening a position. FINRA rules require a maintenance margin of at least 25%, though most brokers set it at 30–40%. Margin amounts fluctuate daily as market prices change.

Futures margin is a performance bond (good-faith deposit) set by the exchange, not a loan. It is typically 3–15% of the notional contract value. Unlike Reg T equity margin, futures margin does not involve borrowing — you are simply required to have enough cash to cover potential daily losses.

Naked short options require significant margin, typically calculated as 20% of the underlying value plus the premium received, less any out-of-the-money amount, with a minimum of 10% of the underlying value. Spreads and covered positions generally require less margin.

If your total margin requirement exceeds your account equity, you will receive a margin call requiring you to deposit additional funds or reduce positions. Brokers may liquidate positions without notice if a margin call is not met within the required timeframe.