Understanding Compound Interest

Compound interest means earning interest on your interest. Over time, it can grow your money significantly.

What is Compound Interest?

With simple interest, you earn a fixed amount each period. With compound interest, the interest you earn is added to the principal, so you earn interest on the growing balance. That growth accelerates over time.

The Formula

The standard formula is: A = P(1 + r/n)^(nt). A is the future amount, P is principal, r is the annual rate (as a decimal), n is how often interest compounds per year, and t is time in years.

📊 Use our Compound Interest Calculator to see how much you could earn.

Compound Frequency

Interest can compound yearly, quarterly, monthly, or daily. More frequent compounding means slightly higher returns. For example, 5% APR compounded monthly yields a bit more than 5% compounded yearly.

Why It Matters

Savings — High-yield accounts and bonds use compound interest
Investments — Long-term growth in stocks and ETFs compounds
Debt — Credit cards and loans compound against you, so pay them down

Related guides

Explore more on Stascash:

Understanding Simple Interest — interest on principal only
Savings Goal Calculator — how long to reach a target with monthly contributions
The Rule of 72 — how long to double your money
Compound Interest Calculator — see growth over time

For informational purposes only. Not financial advice.