Compound Interest Calculator

Calculate the future value of your investments and see how your wealth grows over time with the power of compounding.

Investment Details

Future Value of Investment
$1,628.89
Total Interest Earned $628.89
Total Investment $1,628.89

How This Compound Interest Calculator Works

Our calculator uses the compound interest formula to show you the growth of your investment over time. It takes into account the principal amount, interest rate, time, and compounding frequency to give you a detailed breakdown of your investment’s future value.

1. The Input Phase

Start by entering your Principal, which is the initial amount of money you're investing. Then, input the Interest Rate as a percentage, and specify the Time in years that you plan to keep the money invested. Lastly, choose how often the interest compounds.

2. The Formula

The compound interest formula used is:

A = P (1 + r/n)^(nt)
  • A — Future Value of the investment.
  • P — Principal Investment.
  • r — Annual Interest Rate (decimal).
  • n — Number of times the interest is compounded per year.
  • t — Time in years.

What the Results Show You:

  • Future Value: The total value of your investment at the end of the given time period, including interest earned.
  • Total Interest: The amount of interest earned during the investment period.

Compound Interest FAQ: Everything You Need to Know

What is compound interest?
Compound interest is the interest calculated on the initial principal and also on the accumulated interest from previous periods. This causes the investment to grow at an accelerating rate over time, because each period you earn interest not only on your deposit, but also on all previously earned interest.
How often should interest compound?
The frequency of compounding depends on the investment product you choose. It could be annually, quarterly, monthly, or even daily. The more frequent the compounding, the faster your money grows, because interest is added to the balance more often and starts earning its own interest.
What’s the difference between simple and compound interest?
Simple interest is calculated only on the original principal, so the interest amount stays the same every period. Compound interest is calculated on the principal plus all accumulated interest, so the amount you earn grows each period. Over long time frames, compound interest can result in much higher returns than simple interest.
Can I use this compound interest calculator for retirement planning?
You can use this calculator as a rough starting point for retirement planning by estimating how a lump-sum investment might grow over time. However, the tool does not model payroll contributions, changing interest rates, taxes, or inflation. For detailed retirement planning, you should combine this calculator with a more advanced planning tool or professional advice.
What interest rate should I enter in the calculator?
Enter the expected annual rate of return for your savings account or investment, expressed as a percentage. For example, if a bank account pays 4% per year, type “4” in the interest rate field. Remember that real-world returns can vary, so this is an estimate, not a guarantee of future performance.
Does this calculator include monthly deposits or recurring contributions?
This compound interest calculator focuses on a single initial deposit and does not add recurring monthly contributions. If you want to approximate regular deposits, you can run several scenarios with different starting amounts or time periods. In the future, you may want to use a dedicated investment or savings goal calculator that supports recurring payments.
Does the calculator account for inflation, taxes, or fees?
No, the calculator works with pure math only and assumes a constant nominal interest rate with no taxes, fees, or inflation. It shows how the balance grows in absolute terms. If you want to estimate “real” growth, you can mentally subtract expected inflation and taxes from your chosen interest rate before entering it into the calculator.
Is compound interest always better than simple interest?
For investors, compound interest is usually better because it grows your money faster over time. However, when you borrow money (for example, on a loan or credit card), compound interest can work against you and make debt more expensive. That’s why it’s important to understand where compound interest helps you grow wealth and where it increases your costs.