Compound Interest Calculator
Calculate investment growth with compound interest.
Growth Over Time
ℹ️ About Compound Interest Calculator
This compound interest calculator projects what an investment grows to from a starting balance, a monthly contribution, an annual rate and a time horizon, compounding annually, semi-annually, quarterly, monthly or daily. It splits the future value into the money you put in and the interest earned, expresses that interest as a percentage of contributions, and plots year-by-year growth. Useful for comparing savings rates or seeing how much a modest monthly deposit matters over decades. Your figures stay in the browser and are never uploaded.
💡 Use Cases
📋 How to use
Enter the lump sum you are starting with in the Initial Investment field, in dollars.
Type what you will add every month into Monthly Contribution, or set it to 0 for a single one-off deposit.
Set the Annual Interest Rate as a percentage, such as 7, and enter how long the money stays invested in Time Period (Years).
Choose a Compound Frequency of Annually, Semi-Annually, Quarterly, Monthly or Daily to match how your account credits interest.
Read the four tiles that update as you type: Future Value, Total Contributions, Total Interest Earned and Interest Percentage.
Scan the Growth Over Time bar chart underneath to see how the balance accelerates year by year.
💎 Pro Tips
- Enter your values carefully — small differences in inputs can lead to large changes in the Compound Interest Calculator result, especially for long time periods.
- Use the Compound Interest Calculator to compare multiple scenarios side by side. Open the tool in several tabs to see how different assumptions impact your outcome.
- Bookmark this Compound Interest Calculator and return whenever your situation changes — small updates in income, rates, or expenses are easy to recompute.
- Export or copy the result before closing the tab. Since the Compound Interest Calculator stores no data server-side, your inputs reset when you navigate away.
- Combine this Compound Interest Calculator with our other financial tools (loan, tax, budget calculators) for a more complete financial picture.
❓ Frequently Asked Questions
Yes. The Compound Interest Calculator is 100% free, with no signup, no paywall, no limits, and no watermarks on results. You can use it as often as you need.
No. The Compound Interest Calculator runs entirely in your browser. Your inputs stay on your device and are never transmitted to our servers, guaranteeing privacy.
The Compound Interest Calculator uses industry-standard formulas and returns mathematically precise results based on the inputs you provide. Always verify with a professional advisor for major decisions.
Yes. The Compound Interest Calculator is fully responsive and works on iOS, Android, and all modern mobile browsers with no app install required.
After the initial page load, most calculations run offline because the logic runs in JavaScript on your device. If you lose connection mid-session, you can usually keep calculating.
While the Compound Interest Calculator provides accurate computations, it does not replace professional advice. For tax, legal, medical, or major investment decisions, consult a certified advisor.