Compound Interest: How It Works and Why You Should Use It

Maud Evans
5 min readApr 19, 2023
Photo by Scott Graham on Unsplash

Compound interest is a powerful financial concept that can have a profound impact on your wealth over time. It is a type of interest that is calculated not only on the initial principal but also on any accumulated interest that has been earned on that principal. Essentially, compound interest is interest on interest, and it can quickly snowball into significant returns over the long term.

In this article, we will explore what compound interest is, how it works, and why it is such an important concept for investors and savers to understand. We will also provide some practical examples of how compound interest can be used to your advantage and some strategies for maximizing the benefits of compound interest in your own financial planning.

What is compound interest?

At its core, compound interest is simply the addition of interest to the principal sum of a loan or investment. But unlike simple interest, which only earns interest on the initial principal, compound interest allows you to earn interest on both the initial principal and any accumulated interest that has been earned on that principal. This means that over time, the amount of interest earned on an investment can grow exponentially, making it a very powerful tool for building wealth.

How does compound interest work?

To understand how compound interest works, let’s consider a simple example. Let’s say you invest $1,000 in a savings account that earns an annual interest rate of 5%. At the end of the first year, you will earn $50 in interest, bringing your total account balance to $1,050. Now, in the second year, you will earn 5% interest not only on your initial $1,000 investment but also on the $50 of interest that you earned in the first year. So, instead of earning just $50 in interest in the second year, you will earn $52.50, bringing your total account balance to $1,102.50.

This might not seem like a significant increase, but the power of compounding really starts to show over longer periods of time. Let’s say you leave your money in the savings account for 10 years. At the end of that time, your initial $1,000 investment will have grown to $1,628.89, with $628.89 of that being earned from compound interest alone.