Compound Interest Calculator — Free Online Tool
See how your money grows with compound interest at any compounding frequency.
About Compound Interest Calculator
The Compound Interest Calculator shows how an investment or deposit grows when interest is added back to the balance and then earns interest of its own. Enter your principal, annual rate, time in years and how often interest compounds to see the final amount and the interest earned.
Compounding frequency makes a real difference, so the tool lets you compare annual, semi-annual, quarterly, monthly and daily options. It is ideal for planning savings, fixed deposits or any long-term investment, and every calculation stays on your device.
How to Use Compound Interest Calculator
- Enter the starting principal amount.
- Type in the annual interest rate as a percentage and the time in years.
- Choose how often the interest compounds from the dropdown.
- Click "Calculate" to see the final amount and total interest earned.
Key Features
Supports annual, semi-annual, quarterly, monthly and daily compounding
Shows both the final amount and the interest earned
Handles any principal, rate and time period
Clear, formatted currency-style results
Runs fully in your browser with no data sent away
Frequently Asked Questions
How is compound interest different from simple interest?
Simple interest is calculated only on the original principal, while compound interest is calculated on the principal plus any interest already added, so it grows faster over time.
What formula does this calculator use?
It uses A = P(1 + r/n)^(nt), where P is principal, r is the annual rate, n is the number of compounding periods per year and t is the time in years.
Does compounding frequency really matter?
Yes. The more often interest compounds, the more you earn for the same rate, because interest starts earning interest sooner. Daily compounding beats annual compounding.
Can I use this for loans as well as savings?
You can estimate how a debt grows with compounding, but for monthly loan repayments use a dedicated EMI calculator instead.