Ameris Bank | Explaining Credit Card Interest and Compound Savings to Teens

August 28, 2026

Money Management Family Finances

Educating your teen about money management is an invaluable lesson that can greatly impact their current lifestyle and future financial well-being. This knowledge can help them make informed decisions and achieve their financial goals, such as buying a car, funding a vacation or saving money for the long term. Two key components of this education are credit card interest and compound savings, concepts that many teens do not fully understand.

Read on to learn useful information and read about real-life examples to help you explain these two financial concepts to your teen more easily. Additionally, we provide tips for encouraging them to develop early saving habits.

Interest 101: Start With The Basics

Before discussing credit card interest with your teen, it's helpful to start with a basic explanation of how interest works. As you know, interest is the cost of borrowing money. To illustrate how interest works to your teen, consider an example they can relate to, such as the following:

If you borrow $50 from a friend and they say that you need to repay them $55 within the next two weeks, the additional $5 is the interest you owe your friend for borrowing the $50.

Once your teen grasps the concept of interest, you can explain how it accrues through the use of a credit card. Here is an example:

If your credit card has a zero balance and you make a $180 purchase, then make a $30 payment before the due date, your new balance will be $150. This means you will be charged interest on the remaining balance of $150.

Break Down How Credit Card Interest Is Calculated

After discussing the concept of interest with your teen, you can explain how credit card interest is typically calculated and what contributes to the amount of credit card interest owed. Start by providing a succinct definition of credit card interest, such as this:

Credit card interest is a fee charged by your bank or lender for the unpaid balance on your credit card account.

Let us use the example from the previous section of this blog post to show how much interest would be charged on a $150 credit card balance. You can convey it to your teen in this manner:

If your credit card has a $150 balance and a 20% monthly interest rate, the interest added would be $2.50.

To help your teen understand how this interest is calculated, show them the formula in writing. Here are the three steps:

Divide the interest rate by the number of months in a year (20% ÷ 12 = 1.67%).
Multiply the $150 monthly balance by 1.67% ($150 x 0.0167% = $2.50)
Add the monthly balance to the monthly interest to get the new monthly balance due ($150 + $2.50 = $152.50)

Explain How To Avoid Common Credit Card Debt Traps

Your teen needs to know how credit card interest accumulates and the potential risks of carrying excessive credit card debt. To assist them, explain that when they carry a balance on their credit card and make additional purchases, interest will grow based on their average daily balance and the annual percentage rate (APR).

Compound Savings 101: A Primer For Your Teen

After going over credit card interest—money your teen pays when they don't pay their monthly credit card bill in full—it's time to discuss something they will likely be excited to learn about: compound saving.

Compound Savings By The Numbers

It's important for your teen to have a realistic understanding of the potential compound interest they can earn. They should take into account factors such as their savings account balance, the interest rate and how often the interest is compounded (e.g., daily, monthly, quarterly or annually). You can use the following example to give your teen an idea of how much compounded interest can be earned based on certain parameters:

Let's say you deposit $5,000 into your bank savings account with a 1% annual percentage yield (APY) that is compounded monthly, and you deposit $50 each month for two years (an additional $1,200). After two years, your $6,200 in deposits will earn $112.53 in interest, bringing your savings account balance to $6,312.53.

While the compounded interest in this example may seem minimal to your teen, it is still money earned. Remind them that the amount of interest earned will increase if larger deposits are made and if the balance is maintained.

We want to remind you that calculating compound interest can be complex and time-consuming; the formula is A = P(1 + r/n)^(nt).

A = amount
P = principal
r = rate of interest
n = number of times interest is compounded per year
t = time (in years)

You and your teen can save time by using the free online compound interest calculator on Investor.gov, an official U.S. Government website that provides information and tools individuals need to make sound investment decisions. The calculator gives instant results based on the information entered.

Encourage Your Teen to Develop Early Saving Habits

Saving money can be difficult for teens because they always have something to buy, such as meals, clothes, gifts for friends, concert tickets, or new gadgets. Therefore, it's vital to help your teen develop good saving habits as early as possible. Learning how to save money and budget wisely is a valuable lesson that will benefit your teen in adulthood, especially when making large purchases such as a home.

Begin by introducing your teen to practical financial tools, such as a savings account for setting aside money for the future and a checking account with a debit card for everyday spending and bills. Explain the importance of making regular deposits into each account and maintaining the required minimum balance to avoid potential bank fees.

Finally, remind your teen that saving money for both short-term and long-term goals requires discipline and commitment, and that making unnecessary purchases or excessive withdrawals undermines those goals.

Teaching your teen about credit card interest, compound savings and the importance of saving money doesn't have to be complicated or time-consuming. By explaining these concepts in simple terms and using real-world examples they can relate to, you can help them realize the importance of saving, borrowing and spending money wisely.

We offer savings and checking accounts, along with digital banking tools to help your teen start saving.

The opinions voiced in this material are for general information only and are not intended to provide specific advice or recommendations for any individual. Ameris Bank does not endorse nor is affiliated with the companies listed in this article.