The interest rate for a contribution is one of profitability indicators. Therefore if you store money in bank, you need to be able to consider difficult percent that is when percent increase to the sum of a contribution and then too participate in calculation.
It is required to you
- calculator
Instruction
1. Use for calculation of difficult percent the following formula summa=s×(1+p/100) ^n where summa is final profit, s is the initial sum of a contribution, p – annual percent, that is an interest rate, n – the number of years, months, days (period). For example, let you opened a contribution and put into the account of 10000 rubles under 5% per annum for 3 years. To learn what sum will be on your account for the end of term, use the above-stated formula, that is summa=10000×(1+5/100) ^3=11576.25 river. Then your profit in 3 years will be equal to 11576.25−10000=1576.25 rubles.
2. Use the following formula of calculation of difficult percent for various periods of charge of percent: summa=s× (1+ (p/100) × (g/y)) ^n, where g – the number of days through which period is made capitalization, that is charge of percent, thus, g=30 if percent charge monthly, and g=90 if capitalization of percent is carried out quarterly, y – the number of days in a year (365 or 366 days).
3. For the best understanding, review an example. Let you open a contribution under 6% per annum, capitalization of percent is carried out monthly, initially into the account you put 10000 rubles. Then your sum on the account in 4 months will be summa=10000× (1+(6/100)×(30/365)) ^4=10198.72 river. Let now your contribution of 10000 rubles be open under 6% per annum with capitalization of percent quarterly. Then the contribution sum in half a year will be summa=10000× (1+(6/100)×(90/365)) ^2=10298.08 river. There is g=2 as for half a year at such type of capitalization the percent will be charged twice.
4. Using this formula, it is possible to express an interest rate and the number of months (years). For calculation of an interest rate use a formula p=((summa/s) ^(1/n) −1) ×100. For example, under what percent it is necessary to put the sum of 10000 rubles that in 5 years on the account there were 15000 rubles – p= (15000/10000) ^1/5−1) ×100≈8.5%. For calculation of the period use the following formula n=log<1+ (p/100>) (summa/s). For example, how many years will be required that the contribution by 10000 rubles under 6% per annum increased to 15000 rubles – n=log <1+(6/100)> (15000/10000) ≈7 years.