If a person has a need for additional income, then the easiest way may be a bank deposit with monthly interest payments. Then the question arises about the value of such deposit to profit from it equal a certain amount. Of course, this sum is not small, but usually a few times in her life, she is available to most people. Then the person has a choice – either spend it on durable goods consumption (cars, apartments), which, however, will generate a negative return on content. On the other hand, this amount can make a substantial asset with an income that will be important for the owner. Here I show the calculation of this magnitude. Assume that the consumer needed extra income as a share of (n) of their basic income (salary – Z). Period of payments is a month for which the consumer receives the interest with your deposit of size N, with an annual interest rate r.
! in the formula must be substituted values of n and r is not in percentages but in fractions of a unit (for example, instead of 30% must be substituted 0,3) Thus, we need the amount of interest on deposits for the month equal to a percentage of salary consumer: N – size of the deposit, Z – Salary consumer, n – the share of additional income from wages (for example, 0,4 ie 40%), r – the annual deposit rate (eg 0.13). Example. Let us obtain the average salary of 15,000 rubles, and want to earn extra income in the amount of 40% (n) of the salary. We want to open a deposit with an annual rate of 14% (r), so the monthly interest on it were equal to this additional income. Thus, we need a deposit of 514,000 rubles to receive monthly interest equal to 6000 rubles. (= 40% of salary). In this case, the deposit amount remains unchanged.
However, even if a deposit is not reduced nominally, its real value declining inflation. To take into account the impact of inflation, interest must be received divided by the part that will increase the deposit in proportion to inflation, and the remainder used as additional income. Assume that inflation in the year amounts to inf (for example, 11%), then the formula will change as follows: In recent years, the inflation rate is comparable with the rates on deposits, so you should look for other investment assets that provide returns of 20%. These may make structured products (eg, ordinary deposit + option to oil, etc.).