      Use the following formula to calculate the trading capital (C)necessary to support yourself for a year (S), after taxes (T), given a rateof return (R). Since most brokers do not charge interest on intradaymargin, it is advantageous to use margin for Day Trading. The "2" in thefollowing formula represents 2 to 1 margin. If you choose not to usemargin, then remove the 2 from the formula.