Compound Interest Calculator
Free compound interest calculator with monthly contributions. Compare yearly, quarterly, monthly or daily compounding and see a year-by-year table. Private.
- No upload — 100% private
- Instant, on your device
- Free, no sign-up
- Works offline once loaded
How it works
How to use Compound Interest Calculator
Enter your starting amount and pick a currency.
Enter the annual interest rate and how many years to invest.
Choose how often interest compounds — yearly, quarterly, monthly or daily.
Optionally add a monthly contribution, then read the final balance, contributions and interest.
Scroll the year-by-year table or download it as CSV.
Why use it
Why use our Compound Interest Calculator tool
Four compounding frequencies
Yearly, quarterly, monthly and daily, with the effective annual rate (APY) shown for each.
Monthly contributions
Add a regular deposit to see how saving a little every month snowballs over time.
Year-by-year table
Money added, interest earned and the running balance for every year of the term.
CSV export
Download the yearly breakdown to open in Excel or Google Sheets.
15 currencies
Format results in USD, EUR, GBP, INR, PKR, AED and more, the local way.
Private
Your savings figures are calculated on your device and never sent anywhere.
FAQ
Frequently asked questions
What is the compound interest formula?
A = P × (1 + r/n)^(n × t), where P is the starting amount, r the annual rate as a decimal, n the number of compounding periods per year and t the number of years. 10,000 at 5% compounded yearly for 10 years grows to 16,288.95.
How much difference does compounding frequency make?
More frequent compounding earns slightly more. 10,000 at 5% for 10 years becomes 16,288.95 yearly, 16,470.09 monthly and 16,486.65 daily. The effective annual rate shows the true yearly return.
How are monthly contributions handled?
Each contribution is added at the end of the month and then grows at the monthly equivalent of your chosen compounding. With monthly compounding this matches the standard future value of an annuity formula.
What is APY or effective annual rate?
It is the rate you would need with yearly compounding to get the same result: (1 + r/n)^n − 1. A 12% rate compounded monthly has an APY of about 12.68%.
Does the calculator include tax or inflation?
No. It shows nominal growth before tax, fees and inflation. To estimate real growth, subtract the expected inflation rate from the interest rate.
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