Compound Interest Calculator — Future Value Finder

A Compound Interest Calculator is a financial tool that estimates the growth of an investment over time by applying interest to both the initial principal and the accumulated interest from previous periods. Use OrangeTool to project your wealth with 100% privacy and accuracy.

🏦 Accurate — standard A = P(1+r/n)^nt formula 🔒 Private — your financial data stays on your device 📈 Visual — breakdown of principal vs. interest 📅 Last updated: May 2026

The Power of Compounding

Albert Einstein famously called compound interest the "eighth wonder of the world." Unlike simple interest, which is calculated only on the initial amount you invest, compound interest is calculated on the initial principal plus the accumulated interest from previous periods. This creates a "snowball effect" where your wealth grows at an accelerating rate over time.

Simple vs. Compound Interest

To understand the difference, imagine you invest 10,000 at a 10% annual rate for 3 years:

The gap might seem small initially, but over 20 or 30 years, compound interest can result in hundreds of percent more wealth than simple interest.

Frequency Matters

The "frequency" of compounding determines how often the interest is added back to your principal. Common frequencies include:

Privacy and Financial Security

When you use online financial calculators, you are often providing sensitive details about your net worth, savings goals, and income. Many sites sell this data to banks and insurance companies. OrangeTool never sees your data. Our calculator runs entirely on your local machine using JavaScript. We don't have a database, and we don't track your calculations. Your financial future is your business alone.

Frequently Asked Questions

Does this tool account for taxes?

No. This calculator provides the "gross" future value. Depending on your country and the type of investment, you may need to pay capital gains or income tax on the interest earned.

Can I add monthly contributions?

This tool is for a one-time lump-sum investment. If you are looking to invest a fixed amount every month, please use our SIP Calculator.

What is the 'Rule of 72'?

It's a mental shortcut. If you want to know how long it takes to double your money, divide 72 by the interest rate. For example, at 6%, it takes 12 years (72/6) to double.