Compound Interest Calculator
Project how an initial principal grows with compound interest, with optional periodic contributions and a choice of compounding frequency from daily to annual. Runs in your browser.
About Compound Interest
Uses A = P(1 + r/n)^(nt) plus the future value of an ordinary annuity for periodic contributions. For simple interest use theInterest Calculator, and for monthly investing use the SIP Calculator.
Secure & Private Client-Side
This tool runs entirely in your browser. No data is sent to any server, ensuring your information remains private and secure.
About Compound Interest Calculator
Project how an initial principal grows with compound interest, with optional periodic contributions and a choice of compounding frequency from daily to annual. Runs in your browser.
Frequently Asked Questions
What formula is used? expand_more
Future value = P(1 + r/n)^(nt) for the principal, plus the future value of an ordinary annuity for contributions: PMT * (((1 + r/n)^(nt) - 1) / (r/n)).
Which compounding frequency should I pick? expand_more
Match it to how often the interest is actually credited. Savings accounts often compound daily or monthly; bonds and CDs often compound semi-annually.
How do contributions affect the result? expand_more
Contributions are added at the end of each compounding period and grow with interest. Increasing the contribution has a larger effect than increasing the rate for most scenarios.
How does this differ from simple interest? expand_more
Simple interest is calculated only on the principal. Compound interest is calculated on principal plus accumulated interest, which grows exponentially over time.
Is this financial advice? expand_more
No. This is a planning estimate assuming a constant rate. Real returns fluctuate and fees, taxes, and inflation are not included.
Common Use Cases
- Retirement: Project how a lump sum grows over decades.
- Savings Goals: See what monthly contributions are worth over time.
- Loan Comparison: Compare compound growth to fixed deposit rates.
- Education Fund: Estimate a child's college savings trajectory.