# Compound Interest calculator

#### What is compound interest

When you borrow money from a bank, you pay interest. Interest is really a fee charged for borrowing the money, it is a percentage charged on the principle amount for a period of a year - usually.

#### Compound Interest formula

$$S = P \left(1 + \dfrac{j}{m}\right)^{mt} \ \$$ where:

 $$S$$ is value after $$t$$ periods $$P$$ is principal amount (initial investment) $$t$$ is number of years the money is borrowed for $$j$$ is annual nominal interest rate (not reflecting the compounding) $$m$$ is number of times the interest is compounded per year