Questions : How is compound interest calculated when it's compounded more frequently than annually?
Answer:
Use the formula:
where:
- is the principal amount,
- is the annual interest rate,
- is the number of times interest is compounded per year,
- is the time in years.
Additional Information
Let's break down how to calculate compound interest. It's a powerful concept where you earn interest not only on your initial principal but also on the accumulated interest from previous periods.
Understanding the Terms
- Principal (P): The initial amount of money you invest or borrow.
2 - Interest Rate (r): The annual percentage rate (APR) expressed as a decimal (e.g., 5% = 0.05).
- Number of Times Interest is Compounded per Year (n): How often the interest is calculated and added to the principal (e.g., annually, quarterly, monthly, daily).
3 - Time (t): The number of years the money is invested or borrowed for.
4 - Future Value (A): The total amount you'll have after the time period, including both the principal and the accumulated interest.
The Formula
The formula for compound interest is:
A = P (1 + r/n)^(nt)
Let's Walk Through an Example
Suppose you invest $1,000 (P) at an annual interest rate of 6% (r = 0.06), compounded quarterly (n = 4), for 5 years (t).
-
Plug in the values:
A = 1000 (1 + 0.06/4)^(4*5)
-
Simplify inside the parentheses:
A = 1000 (1 + 0.015)^(20)
-
Calculate the part in the parentheses:
A = 1000 (1.015)^(20)
-
Raise 1.015 to the power of 20:
A = 1000 (1.346855) (approximately)
-
Multiply by the principal:
A = $1346.86 (approximately)
So, after 5 years, you would have approximately $1346.86 in your account.
Key Points
- The more frequently interest is compounded, the faster your money grows.
6 Daily compounding will result in slightly more interest than quarterly compounding, which will be more than annual compounding, and so on.7 - Compound interest can work for you (investing) or against you (loans). It's a powerful force!
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