Simple vs. Compound Interest: What You Need to Know

Understanding the Basics

When you borrow money or invest it, interest is usually calculated in one of two ways: simple or compound. Understanding the difference is crucial for making smart financial decisions.

Simple Interest

Simple interest is calculated solely on the principal amount. If you invest $1,000 at a 5% simple interest rate for 10 years, you will earn $50 every single year. After 10 years, you will have earned $500 in total interest.

Compound Interest

Compound interest, on the other hand, is calculated on the principal amount AND the accumulated interest from previous periods. Using the same example ($1,000 at 5% for 10 years), but compounded annually, your interest grows each year. By year 10, you will have earned $628.89 in total interest.

Why It Matters

When you are investing or saving, you want compound interest. It accelerates your wealth building. Conversely, when you are borrowing money (like a credit card), compound interest works against you, causing your debt to grow rapidly if not paid off.