What Is Compound Interest?

Shawn Plummer

CEO, The Annuity Expert

Compounding is a powerful financial tool that allows your money to grow exponentially. It is the process of generating earnings on an asset’s reinvested earnings. In simpler terms, your interest in your investments can also earn interest. This guide will give you a deeper understanding of compounding, how compound interest works, and how to use it to grow wealth over time.

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What Is Compounding?

Compounding refers to combining two or more individual parts or elements to create a new and more complex whole. In other words, combining multiple things produces a more significant result.

This concept is commonly used in various fields, such as finance, chemistry, linguistics, and medicine. For example, in finance, compounding refers to the process of generating earnings from the reinvestment of previous earnings. In chemistry, compounding is mixing multiple chemical substances to create a new compound.

What Is Compounding

What Is Compound Interest?

Compound interest is a type of interest calculation in which interest is earned not only on the initial amount of money but also on any accumulated interest from previous periods. This means that over time, the amount of interest earned can grow at an increasing rate.

For example, if you invest $1,000 in an account with a 10% annual interest rate, at the end of the first year, you would earn $100 in interest. Then, with simple interest, that $100 would be added to your principal, and you would earn another $100 in interest in the second year, and so on.

However, with compound interest, the $100 in interest earned in the first year would also earn interest in the second year. So instead of earning just $100 in the second year, you would earn $110 (10% of $1,100). Furthermore, this compounding effect can continue over time, resulting in a much more significant amount of interest earned than simple interest.

What Does Compound Interest Mean?

How Does Compound Interest Work?

The formula for calculating compound interest is straightforward. It is calculated by multiplying the initial principal by (1 + the interest rate) raised to the power of the number of compounding periods. The longer the investment is left to compound, the more significant the growth becomes.

Use our free online compound interest calculator to see your savings grow!

Examples Of Interest Compounding

Compound interest is earned not only on the initial principal but also on the accumulated interest from previous periods. The more frequently the interest is compounded, the greater the return over time. Here are some examples of interest compounding:

  • Bank Savings Accounts: When you deposit money into a savings account, the bank will pay you interest. If the interest is compounded annually, the interest earned in the first year will be added to the principal, and interest will be earned on the new total in the second year. For example, if the interest rate is 5% and you deposit $1,000, your balance at the end of the first year will be $1,050 ($1,000 + $50 interest), and at the end of the second year, it will be $1,102.50 ($1,050 + $52.50 interest).
  • Certificates of Deposit (CDs): A CD is a savings account requiring you to leave your money with the bank for a specified period in exchange for a higher interest rate. The interest on a CD can be compounded daily, monthly, quarterly, or annually, depending on the terms of the CD. For example, if you invest $10,000 in a 5-year CD with a 2% annual interest rate compounded monthly, your balance at the end of the term will be $11,049.74.
  • Loans: When you take out a loan, you borrow money from a lender and agree to pay back the principal plus interest over time. The interest on a loan can be compounded daily, monthly, or annually. For example, if you borrow $10,000 at a 6% annual interest rate compounded monthly and make monthly payments of $193.33 for five years, you will pay $11,599.51, with $1,599.51 in interest.

In these examples, the interest earned or paid is based on the initial principal and the accumulated interest from previous periods, resulting in compounding returns.

Define Compounding Interest

Compound Interest Formula

The compound interest formula calculates the interest earned on an investment or loan that is compounded over time. The formula considers the principal amount, the interest rate, the number of compounding periods per year, and the period of the investment or loan.

The formula is:

A = P(1 + r/n)^(nt)


A = the future value of the investment or loan, including interest P = the principal amount (the initial investment or loan amount), r = the interest rate (expressed as a decimal), n = the number of times the interest is compounded per year t = the period (in years) of the investment or loan

To use the formula, you would plug in the values for P, r, n, and t and solve for A. For example, if you invest $1,000 at an annual interest rate of 5%, compounded quarterly for five years, the formula would be:

A = 1000(1 + 0.05/4)^(4*5) A = $1,283.35

Your investment would be worth $1,283.35 after five years, with $283.35 in interest earned.

Who Benefits From Compound Interest?

Compound interest can benefit lenders, borrowers, and investors who save or invest their money over time.

Lenders, such as banks or credit card companies, benefit from compound interest because they earn interest on the principal amount of a loan or credit balance and any interest that has accrued. This allows lenders to earn more money over time than with simple interest, which only accrues on the principal amount.

Borrowers can also benefit from compound interest if they can invest or save the money they borrow at a higher interest rate than they are being charged. For example, if someone takes out a loan at 4% interest and can invest the money at a 7% interest rate, they can profit from the difference in interest rates.

Investors can benefit from compound interest when they invest their money in stocks, bonds, mutual funds, or other financial instruments that earn interest or dividends over time. By reinvesting the interest or dividends earned, investors can take advantage of compounding returns and potentially earn more money over time than with simple interest.

Compound interest can benefit anyone who can save, invest, or borrow money over time and use compounding returns’ power.

How to Use Compounding to Your Advantage

Here are some tips on how to use compounding to your advantage:

  • First, start investing early: The earlier you start investing, the more time your investment has to compound, leading to substantial growth over time.
  • Invest regularly: Regular investing is essential for taking advantage of compounding. It allows you to use compounding over an extended period, leading to substantial growth.
  • Choose investments that offer high-interest rates: High-interest rates are essential for maximizing the benefits of compounding. Therefore, look for investments that offer high-interest rates, such as savings accounts, certificates of deposit, and bonds.
  • Reinvest your earnings: Reinvesting your earnings is crucial for taking advantage of compounding. It allows your investment to continue growing, leading to substantial growth over time.
Interest Compounded Meaning

Which types of accounts offer compound interest?

Many types of accounts offer compound interest, including:

  • Savings accounts: Most banks offer savings accounts that earn compound interest. The interest rate may vary depending on the bank and the type of savings account, but generally, savings accounts offer a low to moderate interest rate.
  • Certificates of deposit (CDs): CDs are time deposits that offer a higher interest rate than savings accounts. CDs have a fixed term, typically ranging from a few months to several years, and the interest rate is locked in for the term. In addition, CDs often offer compound interest, meaning the interest earned is added to the principal, resulting in higher returns.
  • Money market accounts: Money market accounts are similar to savings accounts but typically offer higher interest rates. They may also require a higher minimum balance and limit the number of withdrawals per month. In addition, many money market accounts offer compound interest.
  • Retirement accounts: Retirement accounts, such as 401ks and IRAs, are designed to help people save for retirement. These accounts often offer compound interest and benefits such as tax advantages and employer contributions.
  • Investment accounts: Investment accounts, such as mutual funds and brokerage accounts, can offer compound interest. However, the returns on these accounts are not guaranteed and may vary based on the performance of the underlying investments.
What Is Compounding Interest

Investments that can compound your money a little faster

If you’re looking to compound your money faster, there are a few types of compound interest investments you might consider:

  • Stocks: Stocks offer the potential for higher returns than traditional savings accounts or CDs, but they also come with more risk. By investing in a diversified portfolio of stocks, you can potentially earn compounding returns over the long term as the value of your shares increases.
  • Mutual funds: Mutual funds pool money from multiple investors and invest in a diversified portfolio of stocks, bonds, and other assets. Because mutual funds invest in various assets, they can offer a more balanced approach to investing and potentially earn higher compounding returns than individual stocks.
  • Exchange-traded funds (ETFs): ETFs are similar to mutual funds in that they offer a diversified portfolio of assets but trade like stocks on an exchange. This means you can buy and sell ETFs throughout the trading day, making them a more flexible option for investors.
  • Real estate: Real estate investments can also offer compounding returns over the long term. By owning rental property or investing in real estate investment trusts (REITs), you can earn passive income from rental payments or dividends while potentially benefiting from property appreciation.
  • Peer-to-peer lending: These platforms allow investors to lend money directly to borrowers, earning interest. By reinvesting the interest earned, investors can earn compounding returns over time.

Tools for Calculating Compound Interest

There are several tools available for calculating compound interest:

  • Compound interest calculator: Many free online compound interest calculators allow you to input the principal amount, interest rate, number of compounding periods, and period to calculate the future value of your investment or loan.
  • Spreadsheets: You can use spreadsheet programs such as Microsoft Excel or Google Sheets to calculate compound interest. Input the formula for compound interest and use the functions available in the spreadsheet program to calculate the future value of your investment or loan.
  • Financial calculators: Specialized financial calculators can help you calculate compound interest. These calculators often have additional features, such as amortization schedules, showing how your payments are applied to the principal and interest over time. Some popular financial calculators include the HP 12C and Texas Instruments BA II Plus.

Using these tools can help you calculate compound interest quickly and accurately, allowing you to make informed investment and loan decisions.

Earn The Highest Interest Rates On Savings Today

Fixed annuities are almost identical to Certificates of Deposit (CDs) accounts and provide higher interest rates and penalty-free withdrawals for income.

TermInsurance CompanyAPY
N/AMoney Market Account – Optimum Bank5.26%
N/AMoney Market Account – FVC Bank5.26%
N/ASavings Account – CloudBank 24/7 5.26%
12 MonthsBread Savings CD5.50%
48 MonthsClear Spring Fixed Annuity5.15%
5 YearsAthene Fixed Annuity5.30%
10 YearsEquitrust Fixed Annuity6.00%
*Fixed annuities are only for saving money to use in retirement.

Disclaimer: This is a review. The Annuity Expert is not associated with a bank or credit union. However, fixed annuities are sold at most financial institutions. We aim to help you find the highest interest rates for your retirement savings. We may receive a small referral fee if you purchase something using a link in this guide.

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Next Steps

The ability to earn interest on your interest makes compounding so powerful. When you reinvest your earnings, you’re essentially giving yourself a raise. And the more money you have working for you, the easier it becomes to reach your financial goals. Now is the time to start if you’re not already taking advantage of compounding in your investments. With our help, compound interest can work for you and grow your wealth over time. Request a quote from us today, and let’s get started.

What Is Compounding

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Frequently Asked Questions

How does accrued interest factor into the compounding process?

Accrued interest is added to the principal amount, and the total amount earns additional interest during the compounding process, leading to a more considerable final sum.

How do advisory or brokerage services use compounding to benefit their clients?

Advisory or brokerage services use compounding by reinvesting their client’s profits, which allows their investments to grow over time and potentially earn higher returns.

How does compound interest work?

Compound interest is earned on both the principal amount and the accumulated interest. Over time, this can lead to exponential growth in the investment.

How can individuals take advantage of interest compounds to maximize the growth of their investments?

Individuals can maximize their investment growth by investing early, regularly, and for the long term. They can also consider reinvesting their profits and choosing investments with high compounding potential.

simple interest vs compound interest

Simple interest is calculated only on the principal amount, while compound interest is calculated on the principal and any accumulated interest, resulting in faster growth.

definition of compound interest

Compound interest is earned on the initial principal and any accumulated interest, resulting in exponential growth over time.

Shawn Plummer

CEO, The Annuity Expert

I’m a licensed financial professional focusing on annuities and insurance for more than a decade. My former role was training financial advisors, including for a Fortune Global 500 insurance company. I’ve been featured in Time Magazine, Yahoo! Finance, MSN, SmartAsset, Entrepreneur, Bloomberg, The Simple Dollar, U.S. News and World Report, and Women’s Health Magazine.

The Annuity Expert is an online insurance agency servicing consumers across the United States. My goal is to help you take the guesswork out of retirement planning or find the best insurance coverage at the cheapest rates for you. 

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