What is Simple Interest and How is it Calculated?
Simple interest is a type of interest that is calculated only on the initial principal. The interest is calculated by multiplying the principal and the interest rate by the term. This is especially used in short-term loans or simple savings accounts.
Calculation Formula:
Simple Interest = Principal × Interest Rate × Maturity (Years)
Here;
-
Principal (P):
The initial amount deposited or borrowed.
-
Interest Rate (r):
Annual percentage rate (in decimals).
-
Maturity (t):
The period (in years) for which interest will be calculated.
Where is Simple Interest Used?
-
Short Term Loans:
Generally, for debts with a maturity of less than 1 year and not in high volume.
-
Simple Savings Accounts:
In some basic or daily interest calculations of banks.
-
Student Loans:
Some student loans may accrue interest as simple interest until payments begin.
-
Bonds:
Many bonds pay fixed simple interest on the principal.
What is Compound Interest and How is it Calculated?
Compound interest is a type of interest calculated on both the principal and the interest earned in previous periods. It is also known as "interest on interest" and significantly increases the return on long-term investments. Interest is added to the principal at certain periods (such as annually, monthly, daily) and the interest in the next period is calculated on this new total.
Calculation Formula:
Total Accumulated Amount = Principal × (1 + (Interest Rate / Accumulation Frequency))^(Accumulation Frequency × Maturity)
Here;
-
Principal (P):
The initial amount deposited or borrowed.
-
Interest Rate (r):
Annual percentage rate (in decimals).
-
Accumulation Frequency (n):
The number of times interest is added to the principal in a year (e.g. 1 for annual, 12 for monthly).
-
Maturity (t):
The period (in years) for which interest will be calculated.
-
Compound Interest Earnings:
Total Accumulated Amount - Principal.
Where is Compound Interest Used?
-
Savings and Investment Accounts:
In long-term savings such as bank term deposit accounts, mutual funds, and retirement plans.
-
Credit Cards:
The interest accrued on unpaid balances is often compound interest, which can cause the debt to grow quickly.
-
Mortgage Loans:
Interest on long-term debt, such as mortgage loans, is usually calculated on a compound basis.
-
Business Financing:
Many types of long-term debt and bonds operate on the principle of compound interest.