Free Compound Interest Calculator - Grow Your Savings
Calculate compound interest on your savings.
Formula & Methodology
The Compound Interest Calculator grows your principal using A = P(1 + r/n)^(n·t), where r is the annual rate, n is how many times per year interest compounds, and t is the number of years. Each compounding period earns interest on the previous interest as well as the principal, so the balance accelerates over time. The interest earned is the final balance minus what you originally deposited.
- A = P(1 + r/n)^(n·t)
- Interest Earned = A − P
Worked Example
Using the Compound Interest Calculator: apply the formula above to your input values. For instance, A = P(1 + r/n)^(n·t), then Interest Earned = A − P. The tool performs each step instantly and shows the result.
Frequently Asked Questions
What is compound interest?
Interest calculated on your principal plus all previously accumulated interest, so your balance grows faster over time.
How does compounding frequency matter?
Daily or monthly compounding earns slightly more than annual because interest starts earning interest sooner.
What is the difference from simple interest?
Simple interest is only earned on the original principal, while compound interest also earns on accumulated interest.