Interest Calculator – Calculate Simple & Compound Interest Instantly

Want to know how much interest you’ll earn or pay over time? Use our Free Interest Calculator to find out simple and compound interest in seconds. Whether you’re managing savings, planning investments, or calculating loan costs — this tool gives you precise, instant, and reliable results.

Key Features of the Interest Calculator

Simple & Compound Interest: Calculate both instantly with accurate results.
Customizable Time Period: Supports days, months, and years for flexible calculations.
Supports Any Currency: Works for USD, INR, EUR, GBP, and more.
Instant Results: Get your total interest and maturity value instantly.
Works for Loans & Savings: Ideal for personal loans, investments, and bank deposits.
100% Privacy: All calculations happen locally in your browser — no data is stored.
Mobile Friendly: Works smoothly on phones, tablets, and desktops.

How to Use the Interest Calculator

Enter your Principal Amount (the base money you invest or borrow).
Enter the Interest Rate (%) per year.
Enter the Time Period (in years, months, or days).
Select Interest Type — Simple or Compound.
Click Calculate to get your total interest and final amount.
Use Reset to clear values and start again.

Types of Interest Explained

1. Simple Interest (SI)

Simple Interest is calculated only on the original amount (principal). It’s useful for short-term loans or deposits.

Formula: SI = (P × R × T) / 100

2. Compound Interest (CI)

Compound Interest adds interest to your principal periodically (monthly, quarterly, yearly), leading to exponential growth.

Formula: A = P × (1 + R/100)^T and CI = A – P

Benefits of Using This Interest Calculator

Quickly compare simple vs compound interest.
Plan savings and investments with accurate projections.
Estimate loan costs and repayment amounts.
Free and easy to use — no signup required.
Perfect for students, investors, bankers, and financial planners.

Why Choose Our Interest Calculator

Accurate financial formulas and instant output.
Globally compatible with all currencies.
Optimized for SEO, AEO, and Core Web Vitals.
100% browser-based — your data stays private.
Free for personal and commercial use.

Frequently Asked Questions (FAQs)

Q1. What is the difference between Simple and Compound Interest?

Simple Interest is based only on the principal, while Compound Interest includes accumulated interest over previous periods, giving higher returns or costs.

Q2. Can I use this calculator for loans?

Yes. You can easily calculate the total interest on personal, car, or home loans using simple or compound methods.

Q3. Does this support monthly or quarterly compounding?

Yes. You can set compounding frequency to monthly, quarterly, or annually for more precise results.

Q4. Is this tool free?

Yes. Our Interest Calculator is 100% free to use, with no hidden charges or registration.

Q5. Is my data safe?

Absolutely. All calculations happen within your browser; no information is sent or stored online.

Conclusion

The Interest Calculator is your one-stop tool for accurate financial planning. Whether you’re saving, investing, or borrowing, it gives you quick insights into how your money grows or what it costs over time.