Can compound interest work against me?

Yes, and that is exactly what happens with high-interest debt. When unpaid interest is added to the balance and then charged interest itself, the debt grows faster than the headline rate suggests. It is why a credit card balance at 20% or more can snowball, and why paying down the principal early saves more than the interest line alone implies.

GlossaryReference

Compound Interest

Interest earned on both your original money and the interest it has already generated.

What Compound Interest means

Compound interest is interest that builds on itself. When you earn interest, it is added to your balance, and the next period's interest is calculated on that larger total. Over time this creates exponential growth. It works against you on debt (balances grow faster) and for you on savings and investments (balances grow faster). Time is the most powerful ingredient — the earlier you start, the more compounding can do.

Example

Invest $200 a month at an average 7% annual return for 40 years and you'll contribute $96,000 — but the account could grow to roughly $480,000 because of compounding.

Disclaimer

Definitions are simplified for educational use and are not personalized financial, investment, tax or legal advice.

Frequently asked questions

It depends on the account or loan. Many credit cards compound daily, most savings accounts compound monthly, and some models compound continuously. More frequent compounding makes a balance grow a little faster, but over long horizons the bigger levers are how early you start and how much you add — not the compounding schedule alone.

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Compound Interest

What Compound Interest means

Example

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