Compound Interest Calculator
Calculate how savings or investments grow over time with compound interest.
$54,915.51
$34,000.00
$20,915.51
How to Use Compound Interest Calculator
- 1
Enter the initial deposit
Type the starting amount (principal) you are investing or depositing into a savings account.
- 2
Set the interest rate
Enter the annual interest rate as a percentage. This is the rate your bank or investment offers.
- 3
Choose compounding frequency
Select how often interest is compounded — annually, semi-annually, quarterly, monthly, or daily.
- 4
Set the time period
Enter the number of years you plan to save or invest.
- 5
Add monthly contributions (optional)
Enter an optional recurring monthly deposit to see how regular contributions accelerate growth.
Key Features
Flexible Compounding
Choose from annual, semi-annual, quarterly, monthly, or daily compounding to match your account's terms.
Monthly Contributions
Add recurring monthly deposits to see the combined effect of regular saving and compound growth.
Instant Results
Final balance, total contributions, and total interest earned update in real time as you adjust inputs.
Year-by-Year Breakdown
View an optional table showing how your balance grows each year with contributions and interest separated.
Common Use Cases
Savings Goals
See how much your savings account will be worth in 5, 10, or 20 years at your bank's current interest rate.
Investment Planning
Model long-term investment growth by adjusting rate of return, time horizon, and monthly contributions.
Comparing Accounts
Compare different savings accounts by plugging in their rates and compounding frequencies to see which yields more.
Retirement Forecasting
Estimate how much your retirement fund could grow over decades with consistent monthly contributions.
Frequently Asked Questions
What is compound interest?▾
Compound interest is interest calculated on both the initial principal and the accumulated interest from previous periods. Unlike simple interest, your money grows exponentially over time because you earn interest on your interest.
How does compounding frequency affect the result?▾
More frequent compounding produces slightly higher returns because interest is calculated and added to the balance more often. Daily compounding earns more than annual compounding at the same rate, though the difference is often small.
What is the formula used?▾
The tool uses A = P(1 + r/n)^(nt) for the initial principal, where P is principal, r is annual rate, n is compounding frequency, and t is years. Monthly contributions are calculated separately and added to the total.
Is my financial data sent to a server?▾
No. All calculations happen entirely in your browser. Your financial information is never transmitted to any server.