Online Interest Calculator – Instantly Estimate Simple & Compound Interest
💰 Interest Calculator
Calculate simple and compound interest
📊 Results
Your calculation results will appear here
No Results Yet
Fill in the calculator form and click “Calculate Interest” to see your results here.
Related Calculators
Accounting Calculator
Tax Calculator
Loan Calculator
Whether you’re investing savings, repaying loans, or planning your financial future, our Interest Calculator helps you determine how your money grows — or how much you owe — with precise calculations.
This free tool supports both simple and compound interest, offering flexibility for every use case: loans, investments, or education planning.
🧮 What What Is an Interest Calculator?
An Interest Calculator is a tool that lets you estimate interest earnings or payments based on your principal amount, interest rate, time period, and compounding frequency. Use it to:
- Forecast loan costs
- Plan savings growth
- Compare interest types
- Calculate total returns
Perfect for comparing simple vs. compound interest in real-time.
How It Works?
You’ll instantly see:
Why Use Our Interest Calculator?
- Choose between simple & compound interest
- deal for loans, savings, or business planning
- Mobile-optimized, no downloads required
- Easy to modify inputs and re-calculate
- Privacy guaranteed – no data stored
This calculator is based on formulas used by major banks and reviewed by certified finance educators, ensuring accurate and trustworthy results.
Simple vs. Compound Interest
| Feature | Simple Interest | Compound Interest |
| Formula | P × R × T / 100 | P × (1 + R/N)^(N×T) |
| Growth | Linear | Exponential |
| use Case | Short-term loans | Long-term ivestments |
Example Use Case
- Investing $5,000 at 8% interest:
Simple: Straightforward growth - Compound: Interest on interest leads to faster gains
- Choose monthly compounding to simulate real bank scenarios
Want to see post-tax returns? Use our Tax Calculator for accurate earnings after deductions.