What Is Compound Interest?

Compound interest sounds complicated, but the idea is simple: your money earns money, and then that new money can earn money too.

A simple example

Imagine you invest $1,000 and earn 10% in one year.

Start$1,000What you invest
After year 1$1,100+10% = $100
After year 2$1,210+10% = $110

If you earn another 10% the next year, you are no longer earning 10% on just the original $1,000. You are earning 10% on $1,100. That brings you to $1,210.

The extra $10 came from earning a return on your previous return. That is compounding.

Why it matters

Compounding becomes more powerful with time. The longer money stays invested, the more opportunities it has to build on previous gains.

That is why starting earlier can sometimes matter more than investing a much larger amount later. It is also why investors often focus on staying invested for long periods instead of constantly trying to time every short-term move.

The important part: it works both ways

Compounding can help investments grow, but it can also make debt grow faster if interest keeps getting added to an unpaid balance.

So the same mathematical idea can either help you build wealth or make borrowing more expensive.

One thing to remember

Compounding is growth on top of previous growth.

Small returns may not look dramatic at first. But given enough time, they can become much more meaningful.

Try it yourself: open the Grow Investments calculator, enter $1,000, 10% and 2 years, and you’ll get $1,210. Then change the years to 20 or 30 and watch the gap between simple and compound growth widen.

Stay sharp, stay organized.

Educational content, not personalized investment advice. The 10% return is for illustration only; real investment returns vary from year to year and can be negative.

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