Compound interest calculator
Project the future value of an investment or savings account with compound interest and optional monthly contributions.
How it works
With compounding, interest is added to the balance and then earns interest itself. Future value without contributions = P × (1 + r/n)^(n·t).
Monthly contributions are added at the end of each month, and the compounding frequency is converted to an equivalent monthly rate. Results are estimates before taxes and fees.
Frequently asked questions
What is compound interest?
Interest calculated on both the initial amount and the interest already earned, so growth accelerates over time.
How often should interest compound?
More frequent compounding pays slightly more at the same nominal rate; the difference between monthly and daily is small.