Below are margin formulas and calculations you should understand in determining your equity and buying power.  These formulas are the core building blocks from which all margin situations arise.  Learn and know these relationships well and you’ll be much more equipped to control your risk in margin trading.

Equity = Market Value minus Debit Balance

Equity Percentage = Equity divided by Market Value

Equity Requirement = Market Value multiplied by Required Percentage

Excess Equity = Equity minus Equity Requirement (if the result is positive)

Maintenance Margin Call = Equity minus Equity Requirement (if the result is negative)

Reg T Requirement = Market Value multiplied by 50%

Reg T Excess = Equity minus Reg T Requirement