Disclaimer: This calculator is for general informational purposes only and is not financial or investment advice. Real returns vary and are not guaranteed. Consult a qualified financial professional.
About this compound interest calculator
This free compound interest calculator shows how your money can grow over time. Enter a starting amount, an annual interest rate, the number of years, and how often interest compounds. You can also add an optional monthly contribution to see how regular saving accelerates growth. The result shows your projected future value, how much you contributed, and how much is interest earned.
Compound interest means you earn interest on your interest, which is why long-term saving and investing can grow faster than many people expect. Switch the currency to match your country, and experiment with different rates and timeframes to plan your goals.
How to use it
Fill in the starting amount, rate, and years, choose a compounding frequency, and optionally add a monthly contribution. The projection updates instantly.
How compound interest works
Compound interest grows your money on both your original amount and the interest it has already earned. The future value of a lump sum is:
A = P × (1 + r ÷ n)^(n × t)
where P is the starting amount, r is the annual rate, n is how many times interest compounds per year, and t is the number of years. If you add monthly contributions, each one also grows until the end, and the tool adds it all together.
Example calculation
$1,000 at 10% compounded yearly for 1 year grows to $1,100 — $100 of interest. Over more years, the growth speeds up.
Key features
Future value, total contributions, and interest earned
Optional monthly contributions
Choose compounding frequency: yearly to daily
Pick your currency; instant and free
When to use it
Planning savings or investment goals
Comparing accounts with different rates
Seeing the power of regular saving
Estimating retirement or education funds
Frequently asked questions
What is compound interest?
It is interest earned on both your original money and the interest it has already earned, which speeds up growth over time.
Can I include monthly contributions?
Yes. Add a monthly amount to see how regular saving boosts your future balance.
Can I pick the compounding frequency?
Yes, choose yearly, quarterly, monthly, or daily.
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